Whilst we are on about antibody responses, this is a study from UK where people got pfizer or astrazeneca vaccine at about 10-11 week intervals and it was evident that antibody levels dropped overtime, so after “Frazer day” (OK abit amateur dramtics) on monday when we were all let loose to spread virus at will.
Remember that the level of protection could drop a little with time, although the memory B cells will remain…..These will likely be removed by MS treatments. We dont know if this means for protection and whether protection wains, but this type of data is used to support booster jabs. Again the data shows the difference between astrazeneca and pfizer and the level of antibody induced by the two jabs.
Shroti et al. Spike-antibody waning after second dose of BNT162b2 or ChAdOx1 Lancet 2021DOI:https://doi.org/10.1016/S0140-6736(21)01642-1
As we have said many times before most people who get infected with COVID-19 recover quickly. It is however important that we get rid of the virus, because the longer it hangs around the more time the virus has to mutate. This is what is thought to have occurred with the alpha variant. It appeared to have mutiple rounds of mutations due possible to immunosuppression not getting rid of the virus. These mutations may increase infectivity but the fear is that it reduced vaccine efficacy.
Here is an example of someone treated with ocrelizumab being a potential super spreader. with the virus hanging around for a long time. This is an ususual event. So lets hope the manufacturers works out how this effect can be minimised from avoid issues relating to viral escape
Gibson EG, Pender M, Angerbauer M, Cook C, Jones B, Spivak AM, Spivak ES, Swaminathan S. Prolonged SARS-CoV-2 Illness in a Patient Receiving Ocrelizumab for Multiple Sclerosis. Open Forum Infect Dis. 2021 Apr 8;8(7):ofab176. doi: 10.1093/ofid/ofab176.
We describe a case of prolonged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a patient receiving ocrelizumab for multiple sclerosis. Viral RNA shedding, signs, and symptoms persisted for 69 days with resolution after administration of convalescent plasma and antiviral therapy. This case suggests risk for persistent SARS-CoV-2 infection in patients treated with anti-CD-20 monoclonal antibodies and supports a role for humoral immunity in disease resolution.
This is the vaccine paper
Vaccines based on the spike glycoprotein of SARS-CoV-2 are being rolled out globally to control transmission and limit morbidity and mortality due to COVID-19. Current evidence indicates strong immunogenicity and high short-term efficacy for BNT162b2 (Pfizer–BioNTech) and ChAdOx1 nCoV-19 (Oxford–AstraZeneca).Both vaccines are delivered through a prime-boost (Two injection cycle) strategy, and many countries, including the UK, have used dose intervals longer than 3–4 weeks, expecting to maximise first-dose coverage and immunogenicity. With continued high global incidence, and potential for more transmissible SARS-CoV-2 variants, data on longer-term vaccine efficacy and antibody dynamics in infection-naive individuals are essential for clarifying the need for further booster doses.T o identify early indications of waning antibody levels to the spike protein (S-antibody) after complete two-dose vaccination, we did a cross-sectional analysis of fully vaccinated adults (aged ≥18 years) who submitted capillary blood samples for Virus Watch, a longitudinal community cohort study in England and Wales. The study received ethical approval from the Hampstead NHS Health Research Authority Ethics Committee (20/HRA/2320). Sera were tested using Elecsys Anti-SARS-CoV-2 S and N electro-chemiluminescent immunoassays (Roche Diagnostics, Basel, Switzerland); the S assay targets total antibodies to the S1 subunit of the spike protein (range 0·4–25 000 units per mL [U/mL]), whereas the N assay targets total antibodies to the full-length nucleocapsid protein, which we took as a proxy for previous SARS-CoV-2 infection (specificity 99·8% [99·3–100]).5Serological results were linked with demographic and clinical information collected at enrolment and with weekly self-reported vaccination status.
605 adults submitted a valid sample on June 14–15, 2021. 321 (53%) of 605 participants were women, and the median age was 63 years (IQR 58–67). Of 605 participants, 186 (31%) were categorised as clinically vulnerable, 117 (19%) as clinically extremely vulnerable, and 302 (50%) as not clinically vulnerable (additional participant characteristics and definitions of clinical vulnerability. Participants contributed a single sample, taken 14–154 days after their second vaccine dose (median 42 days [IQR 30–53]). 197 (33%) of 605 samples were from BNT162b2 vaccinees and 405 (67%) samples were from ChAdOx1 vaccinees; vaccine type was missing for three (<1%) participants. The median interval between first and second doses was 77 days (IQR 70–78).Participants with previous infection (N-seropositive; n=47) had a median S-antibody level of 9091 U/mL (IQR 3143 to 16 135), with 2·5-fold lower median levels for ChAdOx1 (median 5179 [IQR 2432·5 to 9513·5]) than BNT162b2 (median 13 025 [9091 to ≥25 000]). N-seronegative individuals had seven-fold lower average S-antibody levels than N-seropositive individuals (median 1257 U/mL [616 to 3526]) and six-fold lower median levels were seen after ChAdOx1 (median 864 [IQR 481 to 1395]) compared to BNT162b2 (median 5311 [3133 to 8829]) within this infection-naive group.We examined the distribution of S-antibody levels for confirmed N-seronegative samples 14–20 days, 21–41 days, 42–55 days, 56–69 days, and 70 days or more after second vaccination to infer the general trend in antibody levels with time, stratified by vaccine type, with p values derived from non-parametric tests for trend. We excluded two individuals with shorter dose intervals of 21–28 days (and assumed those missing first dose date had a longer dose interval) as this has been demonstrated (in part, through preliminary data) to be less immunogenic than longer intervals for both ChAdOx1 and BNT162b2, giving a total of 552 individuals included in the analysis.
A significant trend of declining S-antibody levels was seen with time for both ChAdOx1 (p<0·001) and BNT162b2 (p<0·001;), with levels reducing by about five-fold for ChAdOx1, and by about two-fold for BNT162b2, between 21–41 days and 70 days or more after the second dose.
Disclaimer: Please note that the opinions expressed here are those of the author and do not reflect the positions of the Barts and The London School of Medicine and Dentistry nor Barts Health NHS Trust or Queen Mary Univeristy of London.