Testing for antibodies after a COVID-19 vaccine

getting tested for antibodies by blood draw

COVID antibody testing has provided important information to those who have not been able to test for COVID-19 while unwell or tested with PCR too late or early. It has helped people confirm that the illness they experienced was indeed COVID. It also has limitations as some people do not develop IgG antibodies after having COVID-19.

Now, COVID antibody testing is being used as a tool to check whether a COVID-19 vaccine has worked to trigger a sufficient immune response. A new test has become available that not only gives a positive or negative result but also provides a quantitative result, ie. it tells you how many antibodies you have. This test has been referred to as the COVID “vaccine antibody test” in some circles.

Below we have created a patient advisory to answer the most common questions, bring together the most recent research and give you all of the information you need to make an informed choice about COVID-19 antibody testing. We hope it is of help.

Testing after contracting COVID -19

When should I test?

IgG antibodies are detectable from around 24 – 28 days post-infection.

I definitely had COVID -19 but I tested negative – how is this possible?

Not everyone who is infected with COVID develops IgG antibodies. This depends on viral load (how much of the virus you were exposed to), the strength of your primary immune response and other physiological factors.

How long do antibodies stay in the system?

A study conducted in Spain of 70,000 people, found that around 14 – 15% of people shed all of their antibodies within 2 months and for others, antibody levels declined over 3 – 9 months. These findings were echoed by King’s College. Some research suggests that T cells (one of the important white blood cells of the immune system) also play an important part and T cell memory can continue after IgG antibodies are shed.

Covid 19 test next day results

Testing after your COVID vaccination

When should I test after vaccination?

To the best of our knowledge, the best time to test is 28 – 35 days after your second dose. Although you can test for antibodies after your first dose, we don’t know the degree to which a single dose provides a sufficient immune response. The UK government roll-out of the vaccine has delayed the second dose to 3 months after the first, so we understand that you might be keen to be tested between the two. Although we are happy to conduct the test for you, you should be aware that there is no clear evidence available about whether antibodies are detectable after the first dose and when.

According to reports published by AstraZeneca in the Lancet, a single dose of the vaccination resulted in a four-fold increase in antibodies to the SARS-CoV-2 virus spike protein in 95% of participants one month after injection. In all participants, a T-cell response was induced, peaking by day 14, and maintained two months after injection. Neutralising activity against SARS-CoV-2 was seen in 91% of participants one month after vaccination and in 100% of participants who received a second dose. The levels of neutralising antibodies seen in participants receiving either one or two doses were in a similar range to those seen in convalescent COVID patients.

Therefore if you do decide to test after your first dose of the AstraZeneca vaccine, you should aim to test around one month after your vaccination.

We have very limited information on testing after the first dose of the Pfizer or Moderna vaccine.

What test do you use and what does the result mean?

We use the Roche quantitative antibody test for those seeking to check their post-vaccination immunity response. Neither Abbott nor the rapid cassette is advisable for this purpose.

The Roche quantitative antibody test is helpful because it not only provides a positive or negative result but also provides the number of antibodies present. This is helpful to those who also want to monitor their antibody levels over time.

The Roche test has shown 100% specificity and sensitivity after 28 days.

The limitation of testing is that the immune response to the vaccine is multifaceted and not only dependent on levels of IgG antibodies so testing for antibodies will give you a partial picture only.

Can you tell me what level of antibodies is considered a successful immunisation for each vaccine?

Both neutralizing antibodies and T memory cells play a significant role in immune response and protection post-vaccination.  Measuring immunity is a complex process especially when it comes to a new infection such as SARS-COV-2. Scientists are still working to learn what constitutes an effective natural immune response therefore at present it is difficult for scientists to state definitively what a good vaccine-induced immune response would look like and it is not yet known what level, or titre, is needed for protection.

Another significant challenge is the fact that there is no standardised or pre-aligned measurement process across the globe. Each laboratory uses several types of immunoassay to measure the single aspect of the immune response. As a result of this diversity in testing methodologies being carried out in various laboratories around the world, there is currently no definitive set values for a protective immune response. In time, standardisation of assays will occur, allowing the scientific community to build a greater understanding of the immune response to the SARS-CoV-2 virus and further development of vaccines and therapeutics for COVID.

In summary, our test will let you know if you have COVID-19 antibodies and also tell you how many, but we do not have data yet to inform you whether your level is considered a successful immune response to the vaccine dose.


Will you know whether the present antibodies are because of a previous infection or because of my vaccination?

No, we cannot differentiate between the antibodies caused by a past COVID-19 infection and those developed as a response to your vaccination. If you have had a previous COVID infection, you should let your nurse know.

I’ve had my second dose over 28 days ago but I tested negative – how is this possible?

No vaccine is 100% effective and it is possible that you did not have an immunity response to the vaccine.

AstraZeneca Vaccine

The AstraZeneca vaccine is an adenoviral vector-based vaccination. Researchers have taken the genes for the covid spike proteins and modified them into a harmless virus to make the vaccination.

Once the vaccination is given, an immune response is created by the B cells locking onto the spike proteins, which then with the help of T cells will start to proliferate and pour out neutralising antibodies that target the spike protein.

Clinical trials have shown that this vaccination has an efficacy rate of an average of 70%, ranging from 62-90%. The Oxford-AstraZeneca vaccine requires two doses, given four weeks apart, to prime the immune system to fight off the coronavirus.

Pfizer and Moderna Vaccine

Pfizer-BioNTech and Moderna vaccine uses the genetic material of messenger RNA to deliver information to our cells to make spike proteins. The genetic mRNA is destroyed by the cells once the cell’s molecules have read its sequence and built a spike protein.

The T cells recognise the spike protein as a foreign agent and raise the alarm to other immune response cells such as the B cells. The B cells are then activated by helper T cells that will then produce antibodies that target the spike protein.

The Pfizer-BioNTech vaccine requires two injections, given 21 days apart.  Trials of the two mRNA vaccines report efficacies above 90%.

The Moderna mRNA-1273 vaccine is given at a schedule of two doses (100 µg, 0.5 ml each) 28 days apart. If necessary, the interval between the doses may be extended to 42 days. It has overall efficacy of 90-95%.

The current government strategy is to delay the second dose of the vaccine. What do we know about antibody behaviour after only one dose of the vaccination?

The decision by the UK to extend the second dose vaccination is controversial as there is very limited data supporting this decision. This decision is taken by the UK government to protect the greatest number of at-risk people overall in the shortest possible time.

In both Pfizer-BioNTech and AstraZeneca vaccines, the trials did not compare different dose spacing or compare one with two doses.

AstraZeneca has conducted a trial in the UK and Brazil that include participants receiving different spacing between doses. The finding showed that a longer gap (two to three months) led to a greater immune response, but the overall participant numbers were small.

According to Public Health England, the Oxford-AstraZeneca vaccine provides significant protection against hospitalisation from 21 days after dose one until 2 weeks after the second dose. This evidence suggests that the first dose might provide protection against severe COVID-19 disease. MHRA has also stated that, although optimal efficacy was achieved through two doses, both vaccines “offer considerable protection after a single dose, at least in the short term.”

A paper published in the New England Journal of Medicine stated that the efficacy of the Pfizer-BioNTech vaccine was 52.4% between the first and second dose (spaced 21 days apart).

The PHE Green Book indicates that short term protection for this vaccination starts after 10 days from the first dose. Looking at the data from day 15 to 21 on the Phase III trial, they have calculated that the efficacy against Covid-19 symptoms to be at around 89%. However, Pfizer has that there is no evidence of how much the protection lasts beyond 21 days.

How long will my immunity last?

Due to the newness of the vaccination, researchers do not yet know how long protection will last. There is a possibility that the number of antibodies might decline with time but the immune system also contains special cells called memory B cells and memory T cells that might retain information about the coronavirus for years or even decades. Recent research suggests immunity may last 3 – 6 months but this is yet to be confirmed and it is too early to say for certain.

covid testing


AstraZeneca PLC. COVID-19 vaccine AZD1222 showed robust immune responses in all participants in the Phase I/II trial. (https://www.astrazeneca.com/media-centre/press-releases/2020/covid-19-vaccine-azd1222-showed-robust-immune-responses-in-all-participants-in-phase-i-ii-trial.html). Accessed January 2021

AstraZeneca PLC. What does immunogenicity mean in the context of COVID-19 vaccines? (https://www.astrazeneca.com/what-science-can-do/topics/disease-understanding/what-does-immunogenicity-mean-in-the-context-of-covid-19-vaccines.html). Accessed January 2021

Mahase, E. and Lacobucci, C. 2021. Covid-19 vaccination: What’s the evidence for extending the dosing interval?. Article 372:n18

Corum, J. and Zimmer, C. 2021. How the Pfizer-BioNTech Vaccine Works. (https://www.nytimes.com/interactive/2020/health/pfizer-biontech-covid-19-vaccine.html ) Accessed January 2020.

Cohn, A. and Mbaeyi, S.2020. What Clinicians Need to Know About the Pfizer-BioNTech COVID-19 Vaccine. (https://www.cdc.gov/vaccines/covid-19/downloads/pfizer-biontech-vaccine-what-Clinicians-need-to-know.pdf ). Accessed Jan 2021

Covid 19 prevention network. The Science of COVID-19 Vaccines and Monoclonal Antibodies. (https://www.coronaviruspreventionnetwork.org/coronavirus-vaccine-and-antibody-science/ ). Accessed January 2021

Centers for disease control and prevention. 2021. Interim Clinical Considerations for Use of mRNA COVID-19 Vaccines Currently Authorized in the United States.  (https://www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html)

Macdonald, A. 2020. COVID-19 Antibody Testing: S vs. N Protein. (https://www.technologynetworks.com/diagnostics/blog/covid-19-antibody-testing-s-vs-n-protein-340327). Accessed on Jan 2021

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129 Responses

  1. I had the astra veneca vacation on 26th January, and no antibodies on 3rd March, what does this mean and what if any thing do i do regards Barry

    1. hi Barry – what test did you have? Not all antibody testing is appropriate post-vaccine. If you have taken the correct test (quantitative antibody test) that we provide, then this may be that you fall within the 10 – 15% of people for whom the vaccine was not effective. Before we draw that conclusion however, we recommend making sure you’ve had the right test.

    2. Those posting about negative test results (maybe relating to the type of test used) can you include info if you had post vaccine side effects too? i.e. if you suffer the unpleasant inflammatory response – headaches, chills, joint aches etc for up to 48hrs, that is indicative of the T-cell production being kicked into action. With the quantitive antibody tests discussed in the article there should definitely be degrees of positive result with it’s reputed sensitivity. If negative post strong side effects, that leaves unanswered reasoning. I’m sure no side effects can still result positive but can any more posts please include so an overview can be formed please?

    3. I’ve had a antibody test 4 weeks after a Covid jab. Results are that I’ve not contracted Covid 19 but what conserns me is I’ve tested negative for Covid antibodies. Does this mean I’ve to be extra careful? X

    4. I had my second dose of the AstraZeneca vaccine a couple of weeks ago. I did my rapid test for covid-19 antibody and found both IgG or IgM negative. Does the routine rapid antibody test is the best tool to look for antibodies or there is a special rapid test for covid-19 vaccine antibodies ??

    5. My husband had his first phizor vaccination on 23rd January. He had a antibody test on 9th April and he has negative antibodies now.. Does this mean that he has no protection against the virus?

      1. Dear Mr Cain, it depends what antibody test he had. If he has the Roche quantitative antibody test and tests negative, then it is possible he is in the percentage for people for whom the vaccine has not been effective. However, we strongly recommend having the Roche test before making that conclusion as most other antibody tests will test negative for post-vaccination antibodies. Immunity is made up of multiple aspects, one of which is antibodies.

  2. I have read your article. Because I have Myeloma and in light of recent, if inadequate, research I would like to have an antibody test after my second dose of the Pfizer vaccine in April. Could you give an idea of when would be the best time ( ie how long after?) and where I could get this done. I live in Chesterfield, Derbyshire. Perhaps also there is a trial I could participate in to aid knowledge about this issue?

    1. hi Gayle! Based on the research provided by Pfizer and AstraZeneca, 28 days after your dose would be ideal. We aren’t running a trial here due to relatively small patient numbers and only have a branch in Central London. if you test elsewhere, please make sure they provide an antibody test suitable post-vaccine as some antibody tests are not suitable for this purpose.

      1. Hi Alya
        I’m a kidney transplant patient in central London – how far in advance would I need to book to get an antibody test after my second dose of the vaccine? I’m keen to see if there’s any sign of the antibodies, the preliminary results for Pfizer in tx patients in the US don’t look positive!

        1. Hi Ali, thanks for your comment. You can book with us for a same-day or next-day appointment. Ideally, you should book from 28 days after your vaccine dose. Hopefully, the results will be positive for you!

    1. hi Alan! You can book in for a quantitative antibody test with us. You’ll have the result in 24 hours.

      1. I’ve had Pfizer vaccine in February I had an antibodie test April I had antibodies had a blood test in April my antibodies negative how’s that

  3. I have had 1 astra zeneca covid vaccine , I tested negative for antibodies 1 month after what does that mean?

    1. Seems like this is a common theme. I had vaccine same time as a relitivr who had Pfizer, both tested week 3 – they had lots of antibodies, I have none .

      1. hi James – what test did you have? The instant tests and Abbott test aren’t suitable for detection post-vaccine.

    2. Hi Jane – what antibody test did you have? There is only one test that would detect these (the quantitative test we offer). The antibody tests used for post-infection such as Abbott or instant / rapid tests aren’t suitable. Please retest with the quantitative antibody test in the first instance.

    3. I empathise. This is all so confusing.

      I had 2nd AstraZeneca end may 2021 (10 weeks after 1st vax). Mid July did Roche post vaccine quantitative test: 927 u/ml antibodies.

      Did another (same) test last week (4 months after 2nd vax) 345 u/ml antibody level.

      So it was huge decline in 2 months,

      But still why can no-one say what antibody levels DO protect us?
      They talk about t cell immunity even if antibody levels drop, BUT HOW can they prove it to us? To me?

      I am over 60 and am scared to go out because I do not know if this vaccine would protect me at all!!! Are they playing Russian roulette with us? I had metallic taste in mouth immediately after vaccine and strange sense of taste for months (no, I did not contract Covid). I have had LHS above ear headaches since day 1, still now. I have heightened anxiety and brain fog since vax. I did NOT have chills or fever, so did my immune system kickin’ or not?
      I have also done 3 panodyne combined IgG/igM and post vaccine neutralizing antibody tests which showed NO neutralizing antibodies, and also NO igG or igM (,haven’t been exposed to virus so u knew they would be negative!)

      Is the Roche quantitative test reliable or should I test again?

      And what does 345 u/ml antibody leveling indicate? Compared to 927 2 months earlier?

      Can I go out to an event with 100 people ? all who will be unmasked (not sure of mask efficacy to protect ME)

      I have to fly to conference within 2 weeks and am concerned about flight and airports as well.
      Thanks for reading. Your help/answers will be so appreciated.

  4. If you have had both vaccines and the antibody results are negative, what are you expected to do? Thank You

    1. hi Lisa! What antibody test did you have? If you had an antibody test that only gives a positive or negative result, these aren’t appropriate for testing post-vaccination. This is why we recommend the quantitative antibody test we provide. We have had patients who tested negative on tests more suitable post-infection then show antibodies on our test. Please do book in if you’d like to check for antibodies. If that test is then negative, it is possible you are in the 10-15% of people for whom the vaccine is not effective. Hopefully that is not the case. We hope this is helpful.

  5. I had my 2nd Pfizer vaccine 26th Feb and would like an antibody check. Where can I have this done please? I live in Bucks so can travel into London

    1. Hi Paula, you can have this test with us. Go to our online booking and choose A4: COVID-19 quantitative antibody test. We look forward to welcoming you.

  6. Good article – if I’m trying to use the online booking tool to get the Roche test for antibodies after my second dose of the Pfizer vaccine, which test should I be booking from your list? It’s not clear from the list. Thanks!

    1. Hi Ali, please choose “A4 – COVID-19 quantitative antibody test”. Thank you for your feedback.

  7. I had Covid antibodies prior to having vaccine. After 7 days I’m having long covid again. My joints hurt, I feel generally unwell. Should I have second dose of vaccine

    1. hi Linda, sorry to hear you’re not feeling well. There could be a number of causes of your symptoms, including reactivation of glandular fever / Epstein Barr Virus, another viral infection or as you say, long COVID. Symptoms caused by long COVID can come and go. The second dose is what gives longer-term immunity so we would recommend you still have this. Of course, if you are feeling unwell do speak to your doctor and schedule when you are feeling better if this is possible. If you’d like more support on long COVID, you can read our blog post from our sister company and make an appointment with Dr Abood: https://www.harleyhealthcentre.com/blog/coronavirus/covid-19-symptoms-long-covid-empowering-ourselves-with-knowledge-action

      1. Thank you for the reply. I’ve read the link you posted. I take several supplements, including zinc, vitamin D etc. I do think that as I still had antibodies after having Covid last March and five months of long covid, I’d survive getting it again. However, I see your advice us right to continue with 2nd dose

        1. Please could you advise price of the covid-19 post vaccination quantitative antibody test. Could not locate on website. Thanks

  8. I’m part of a Covid study at Oxford University and have had a blood and swab test every month since October. I had my first Pfizer vaccine on 2nd February but no booster yet. My blood and swab test on 02/03/21 showed I was negative for Covid but positive for antibodies. I had another blood and swab test on 27/03/21 but haven’t received the results yet. However today I had some NHS text messages and emails saying I was positive for Covid and I should start isolating immediately. I don’t understand what is happening since I have no symptoms, also shouldn’t I have had my Pfizer second jab by now? Thank you for any advice, from Linda

  9. I’m on the Uk Biobank programme. I had my first Pfizer vaccination on the 25th January 21 which caused a massive bruise.I had my second vaccination on the 31st March. I also carried out an antibodies test for Uk Biobank on the 31st March which proved negative I’m now concerned.

  10. I had my first Pfeizer jab in Dec 2020 followed up with the 2nd one Jan5th 2021. I had a sore arm with the second jab, but nothing more. I tested negative for antibodies at the beginning of March. My GP told me it may be because the government antibody test is testing for C19 antibodies, NOT vaccine antibodies. Can you please enlighten me and direct me to a test, if necessary, relevant to the vaccine?

  11. I am Autoimmune Rheumatoid Arthritis patient and Immunesurpressed I have had one Pfizer jab and had to wait 12 weeks in England for second there are rumours the vacvine has not worked for us would a antibody test after the second jab be helpfull as I have shielded for over a year so I definately have not had it

  12. I live in Cheshire so I can not get to London can I please ask you if an antibody test called VirTus Quantative is the same as yours

      1. Hi
        I had my first jab of Pfizer vaccine in January and 2nd by March but my antibody test came back negative this morning. What should I be worried about and is there anything I can do otherwise to have immunity.

    1. There is no research defining the number of antibodies that would be considered a successful immune response. The quantitative test registers antibody levels in a range of 0.8 – <2000.

  13. I have had 2 blood tests since my Pfizer vaccine, but the results both said negative for antibodies. I am due my second vaccination about 23/24 April. I am keen to get another blood test after this. Can you do this please?

    1. Hi Martyn, do you know what test you had? We recommend the Roche quantitative antibody test. Patients have tested negative with other antibody tests and they do not use the same detection method needed for antibodies generated post-vaccine. You can call us on 020 7323 1023 to book.

  14. Post Astra COVID19 vaccine ,
    When to test ?
    Is it IgG ? / total ?
    Why second dose 3 months & not 1 month as previously ?

    1. Dear Sameh, you can test 28 days after your first and second dose. The test we provide is a Roche quantitative antibody test. It does look for total IgG and gives a quantitative result. You can book this on 020 7323 1023. We are afraid we do not know why the next dose timing has been changed by the government – recent evidence suggests this approach could still provide protection.

  15. My husband had the Sinopharm vaccine (2nd dose on January 31st). He got tested a few days ago and his igG was 17.3. Is that an adequate number of antibodies?

    1. Dear Eman, unfortunately there has been no guidance from the vaccine manufacturers or government regarding expected antibody levels post-vaccine, therefore we cannot in good faith give an answer based in evidence.

  16. I had my second pfizer jab in late February and did an antibody test on the 12.4.21 I got a text to say my test was negative and that I’d not had covid 19 and had no immunity to it should I be concerned.

  17. Hi
    I had my first vaccine (Pfizer) on 13 February.
    I am on a Covid test trial with ONS.
    Blood test for antibodies on 8th March showed positive but on 8th April was negative for antibodies. Does this mean the vaccine is no longer working.

    1. It would be a good idea to test after your second dose. If you then test negative, then you may want to discuss this with your GP.

  18. Hello Alya, I have IgA deficiency and am on Sulphasalazine for PsA. I had AZN vaccine on 8 March (had a high temp., aches and rash for several days afterwards) and antibody test on 12 April (I don’t know what kind of test it was unfortunately). The test came back negative for antibodies. I’m keen to get back into my work office; would you recommend having the Roche Quantative test now or a month after my second vaccine, which is on 24 May? Also, does the Roche test look for spike protein antibodies? I would value your professional opinion.

    1. Hi Megan! At this stage, it would make sense to test after your second dose. The test targets antibodies against the spike protein. This is the focus of vaccines in development and convalescent plasma therapy. I hope this helps!

  19. I had your test after having both Pfizer jabs result 505 .what does that mean in layman’s terms. Thank you

    1. Hello Keith! Thank you for choosing us. This means that you have developed a good number of antibodies. If you’d like to speak to someone about your result, please do not hesitate to contact the clinic.

  20. I have had 2 doses of the Pfizer vaccine and used the Panodyne SARS-COV-2 Combined test. I had a +ve IGg test and a weaker red T line than the C line on the NAb side. I am hoping this means I have some immunity to covid-19 as I am immunocompromised !

    1. The ideal test would be a Roche quantitative test to have a clear idea of your response to the vaccine.

    2. Definitely do a Roche quantitative test. I had barely anything come up on the same Panodyne test, and had a considerable level after vaccination on the Roche test taken a few days later.

      1. I did combined panodyne IgG/IgM and post vaccine neutralizing antibody tests which was negative for NAB antibodies (& igg/igm)… Did 3 of them to check results , all negative.
        Then did the Roche quantitative post vaccine and that showed 927 u/ml antibodies which was good… 2 months later did another test: panodynr still negative… Now Roche quantitative test = 345 u/ml = big reduction. Am concerned

        1. Antibodies do decline over time, so this is normal. Do take up the booster vaccine when it becomes available to you.

  21. I took sinopharm vaccine 2 doses 3 months ago. I took antibody test IgG . The result was 2.69. The test indicate that you need to be 6 and above to be positive. I asked one opinion says I have low level of antibodies. Others say I have no immunity. I still don’t know the correct answer. Anybody who have a comment on that. Thanks

    1. That is a low level of antibodies but immunity is measured by antibodies and other measures. Unfortunately, there is no research that defines what successful immunity looks like in terms of numbers yet so we can only go by comparison. Your result is low. However, we can only imply what that would mean for your protection based on general understanding.

  22. How much is the test. I am immune deficient I took the NHS antibody test after my 2nd vaccine and it came back negative

  23. 10 10/11 weeks I did the London college blood test for antibodies and got a negative result….what does this mean?

    1. We are not aware what test the London college is using so cannot give a definitive answer. If, as we would assume, they are using the correct test, then this means that you did might not have developed antibodies post-vaccine. How many doses have you had?

  24. We had our Roche quantitative antibody tests on 24th May and the results were e-mailed to us on the same day. I had the second dose of Pfizer in January and my wife had her second dose of the same in March. My Roche Anti-SARS-CoV-2-S Result 1773.0 U/mL and my wife’s Roche Anti-SARS-CoV-2-S Result >2500.0 U/mL. What do these mean? Do you provide a report?

    1. These results mean that you are positive for a good number of antibodies. There is no research currently that clearly defines what is a satisfactory immunity response (which would also incorporate other markers) but both of these results are considered a high number of antibodies.

  25. Had AZ vaccine and 2 months later tested negative for antibodies in the Oxford ONS trail test. Should I get the Pfizer one to see if that will protect me I am high risk category GP says

  26. I did my first doze of Pfizer vaccine and need to travel urgently. So I bought Panodyne SARS-CoV-2 Combined test and applied it. Can you please help to interpret the results? Instruction are quite unclear and contradict. I have the following result: IgG/IgM only C line is bright red, G and M do no have any red lines; NAb has C line in bright red while T line in pale red. Does it mean I have immunity against the COVID-19?

    1. Hi Alexey, we cannot vouch for any test other than the Roche quantitative antibody test as accurate post-vaccination. Based on your description, the test you took suggests that that you probably tested negative for antibodies using this test. We recommend having the Roche quantitative test for a definitive answer.

  27. I had 2 x Sinopharm in UAE in Jan and FEb 2021….I am now back in UK…..because of uncertainty on the Sinopharm vaccinations, I had the Antibodies spoike protein blood test. The GP said he was no expert but wld expect a result of between 250 and 1000 although positive results start at above 0.8 on the bloodtest – Roche Antibodies SARS-CoV-2-S Total Ab Positive – is 16 sufficient or shld I look to get a booster now back in UK…I am a 60 yr old male fyi……I believe the UAE are now recommending a Pfizer (NOT AstraZeneca) booster for those with 2 x sinopharm over 60……can you advise as no help from III…..many thks…Mike

    1. As private clinics do not administer the vaccinations, I am afraid we cannot advise you on which vaccine you should have as a booster. We recommend seeking this advice from the clinic that administered your original vaccination. Regarding your antibody levels, it is true that there is no clear guideline as to what would constitute a sufficient immunity response but 16 is at the lower end of the spectrum. Immunity is not solely measured by antibody response, however. We certainly would not recommend being vaccinated beyond the recommended doses or taking boosters before advice / evidence has been provided on this.

  28. For very high risk patients:

    1-What tests are available in the uk to show whether or not 2 AstraZeneca vaccinations have “taken”
    2- If the results do not show that the vaccinations have taken can patients then have Pfizer vaccinations to find out if they then have some immunity rather than remain in total self-isolation forever?
    3- How can these tests and Pfizer vaccinations be obtained and do they have to be paid for privately?
    W Woods

    1. Dear Mr Woods, thank you for your questions. We are not part of the NHS so are unsure what testing is currently being provided or whether you would be eligible for further vaccination should you test negative for antibodies. Privately, we provide the Roche quantitative antibody test which clearly shows the presence of post-vaccination antibodies and provides a quantitative result / level.

  29. I took my first dose Astrazeneca in 22/5/2021 and in 21/6/2021 i felt in runny nose for 3 hr. with no other symptoms And today (22/6/2021) rapid test gave +igm,+igg.. is this result consider me infected or not?
    Pcr was done and waiting for the result

  30. I’ve had both of my AstraZeneca jabs, first in February and second in May. I have just had a Covid antibody blood test which shows I have ZERO antibodies. What should my next step be?

  31. I am a recently retired nurse, before I retired I was called for a routine Hep B antibody screen. I had several vaccinations for Hep B over the years. My result was negative antibodies despite the many booster doses I had.
    I am now concerned I may not have developed antibodies to Covid 19. I had no adverse reaction to the vaccination What should I do now?
    Pat Mellor

    1. Dear Patricia. Firstly, thank you for your service. You would benefit from having a Roche quantitative antibody test. I’d avoid extrapolating from the hepatitis B immunity history although I fully see why you would. Even if you haven’t developed antibodies, you may have T-cells, which can also be tested for. We provide a discount for NHS staff, including retired staff, so get in touch if you’re local.

  32. I had my second vaccine in April, do I still need an antigen test before traveling? can it be booked in NHS?

    1. Hi Edna, this depends on where you are travelling to as each destination has its own requirements. No, you should not book a travel test with the NHS and it is unlikely to be accepted.

  33. Age 77 ,I have had 2 AstraZeneca vaccines, Bio Bank sent an antibody immune test which tested negative.Should I seek another type of vaccine?

    1. Dear Ms Haddow, we aren’t aware of the type of test run by Bio Bank so cannot fully advise. We strongly recommend having a Roche quantitative antibody test which is best suited to tested post-vaccine.

  34. Please i have a question : I developed Covid at the start of 12/2020 , At 21/03/2021 was my ist dose of Astrazeneca vaccine , before i got the shot i did antibody level IGG and it was 65.6 Au/ml , after 12 weeks i received my second Astra dose at 13/06/2021 , then I did antibody level IGG 14 days after 2nd dose and it was 67.8 U/L, Whats your opinion about my immunity please , Am 66 years old physician from Jordan & Diabetic patient type II On Insuline wih mild Hypertnsion.

    1. Dear Dr Malkawi, thank you for your kind question. We unfortunately don’t yet know what level of antibodies would be considered a “successful” immunity response but your result is at the lower end of what is expected and what we have seen. It is possible that you have tested too soon after your second vaccine and should test again to see if that number has increased. You may benefit from a T-spot T-cell test to see if your immune response has favoured this but unfortunately, it is difficult to give a clinical opinion.

  35. I am clinically extremely vulnerable and have a suppressed immune system due to the removal of my spleen after cancer. I have had both doses of the Pfizer vaccine. I would like to know if I now have any antibodies as I am terrified at the possible dangers of contracting covid with the lifting of restrictions in England. Can I get a test and what is the cost? Thank you.

    1. hi Carmel. I’m so sorry that you’ve been made to feel this way. We are very concerned about the impact on clinically vulnerable people of the lifting of restrictions. We continue with the same guidelines and infection control here and can book you in either at the very start or end of the day and create buffer appointments before and after you to reduce any contact you have with others. The cost of the Roche antibody test is £129 or you can have a combined test of the antibody and T-cell test for £245. If you book, please email me in advance and I’ll make sure all of these measures are put in place – [email protected] (I have the same email for our sister company). All the best.

  36. Good afternoon. I have had both doses of Astra Zeneca, my 2nd was in 6th April. As I am on biologic medicine, (Humira) for AS, known to lower immune system, I am worried how much protection do I have from my jabs. I am aware that this is complex but what advice can you offer me? I am still bei g careful although no longer having to shield, its just for my own piece if mind. Thanks vm

    1. Hi Ian. The best way to assess this is with a Roche quantitative antibody test. You could also consider a T-spot test for the presence of T-cells. I hope this is helpful.

  37. I live on the Isle of Wight, and have neutropenia (Felty Syndrome). Had both Astra Zenica vaccines, and would LOVE to know where/how I can get a test to see if I made any antibodies?

    1. Hi Anna! Unfortunately we aren’t familiar with services in your area but vitally, if you contact a private clinic, make sure you have the Roche quantitative antibody test and not the Abbott blood test, which often does not detect antibodies developed post-vaccine.

  38. Hi, Alya Shakir.
    I have questions about antibody blood test kit. Does it shows positive result for igG and igM after vaccinated?

    1. The rapid antibody test kit is not suitable post-vaccination. The Roche quantitative test is the recommended test and will show a quantitative result of the number of IgG antibodies only. you can also have a T-spot test to look for presence of T-cells.

    1. Hi Sharifa – you can test for antibodies post vaccination at any time after 28 days. If you’d like to book with us, please just get in touch with the clinic.

  39. I did catch COVID 19 on 4/4/2021
    Vaccinated Sputnik v on 23/5/2021
    Tested Ig G after 2 months from vaccine.
    Can I got AstraZeneca vaccine or what?
    I am professor Ophthalmolgy 69 years old
    Need your advice please
    Thank you

    1. Thank you for your query, Professor. Unfortunately, data / research on vaccine mixing is currently unclear and we are unable to advise. Have you had a quantitative antibody test at all?

  40. I was tested for antibodies 5 weeks after my second Pfizer jam, due to my compromised immune system, (CLL) the result was negative. I had jab #3 Jul 8th, when is it appropriate to re-test?


    1. Clear guidelines on this are not available but the research suggests testing after 28 days would be optimal.

  41. I got my 1st dose of vaccine on 15th march 2021 and 2nd dose on 15th May 21., both Covi. shield I got tested for IgG on 3rd August The report indicates Negative. {0.28. %} what is the status of my immunity ?. and what should I do further. Thank and regards.

  42. Hi, I’ve got pfizer second dozen 3 weeks ago, is it possible to know, how many antibodies are made? With IGG and IGM test?

    1. Hello. We recommend waiting 28 days post vaccine before testing but yes, we can tell you how many IgG antibodies you have developed post-vaccine. We do not test for IgM (non-specific) antibodies but can also test for COVID-19 related T-cells.

  43. After Phizer vaccination series, due to immunocompromised I show no antibodies. Can I repeat original vaccine series rather than booster?

    1. This will depend on government policy and the booster programme. Unfortunately, there is no clarity on this yet. Sorry you are in this position – we will update our reply if any developments take place.

  44. I have had an antibidy test done by my Rheumatologist and I have no antibodies from my AZ vaccine. How can I ensure that any booster wiuld be Moderna or Pfeizer?

  45. I have had a Roche antibody test by results were >2500, I have been invited to have a booster vaccine. Should I get the booster if my results are showing I have high antibodies

  46. What is the benefit of this test? If I have a positive test then does that mean I don’t need a booster

    1. The benefit of this test is to check your antibody level post-vaccine. Research has shown that this level wanes over time. The booster is recommended regardless of your antibody level to maintain a good level of protection through this winter.

  47. Good morning Ms. Alya,
    I am IRANIAN but got the second doze of AstraZeneca in ARMENIA on August 26, 2021 and yesterday ( October 6, 2021 ) I got the Antibody Vaccine TEST IgG Spike the result is 82.76 Is it OK travel to UAE as vacation and holidays or it has risk again Warmly, Soheila

    1. Dear Ms Soheila, thank you for your question. This will depend on a range of factors including your general health and any underlying conditions. If you are vaccinated, you can travel with more confidence than otherwise. Although the result is at the lower normal end, antibodies only tell 50% of the immunity story, and you may also have T-cells which support your COVID-19 immunity.

    1. Vaccines reduce transmission but do not eliminate it. Vaccines help prevent serious illness and hospitalisation but do not stop you catching the virus.

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