Boosters really don't do much unless you at least get a different vaccine than the original as then at least you have some variety in the potential anti-bodies that you are developing (I had a Pfizer original vaccine and went Moderna on the booster). But I cannot see how taking the same exactly vaccine over and over is going to get much after two shots. It appears to me that you get a 4-6 week 'boost' as your body sees the spike protein and elevates it's defenses which is what you get for that period. Then the body fights it off and you are back to where you started with no additional protection as you already had the anti-body's in your system before the vaccine booster. I think the 4th booster shot really is about worthless and unless I was in the ultra high risk category don't see a reason to get it and the medical science is also showing that.
Lancet again.
Holy crap.
194, 472 users?
For the analysis of vaccine effectiveness of two doses, we included 620 793 UK app users who reported being fully vaccinated and subsequently tested for SARS-CoV-2 with an RT-PCR-based test or a lateral flow test between May 23 (once the SARS-CoV-2 delta [B.1.617.2] variant became predominant) and Nov 23, 2021, and 40 345 unvaccinated users who had a PCR or lateral flow test result in the same period (
appendix p 6). 204 731 (33·0%) individuals received two doses of BNT162b2, 405 239 (65·3%) received two doses of ChAdOx1 nCoV-19, and 10 823 (1·7%) received two doses of mRNA-1273 (demographic characteristics are shown in the
table). The study sample was predominantly female (409 065 [61·9%] of 661 138) and 137 939 (20·1%) were obese (mean BMI 26·61 kg/m2, SD 5·33). On average, fully vaccinated individuals completed their second dose 3·84 months (IQR 3–5) before the analysis.
TableDescriptive characteristics of the study population, by type of vaccine used in the primary immunisation series
| | BNT162b2 (n=204 731) | ChAdOx1 nCoV-19 (n=405 239) | mRNA-1273 (n=10 823) | Unvaccinated (n=40 345) |
---|
Sex | | | | | |
| Female | 134 032 (65·5%) | 242 829 (59·9%) | 6235 (57·6%) | 25 969 (64·4%) |
| Male | 70 699 (34·5%) | 162 410 (40·1%) | 4588 (42·4%) | 14 376 (35·6%) |
Age, years | 50·0 (13·9);52 (38–62) | 54·8 (9·9);56 (48–63) | 39·1 (8·3);39 (33–46) | 37·7 (13·2);34 (27–47) | |
BMI, kg/m2 | 26·6 (5·6) | 26·8 (5·3) | 25·2 (4·6) | 25·4 (5·3) | |
Health-care workers | 27 110 (13·2%) | 9522 (2·3%) | 84 (0·7%) | 1794 (4·4%) | |
Comorbidities | 41 136 (20·1%) | 66 471 (16·4%) | 755 (7·0%) | 3958 (9·8%) | |
Infection post-vaccination | 16 037 (7·8%) | 45 384 (11·2%) | 751 (6·9%) | 6726 (16·7%)
* | |
| PCR confirmed | 11 491 (71·7%) | 32 082 (70·7%) | 525 (69·9%) | 4868 (72·4%)
* |
| LFT confirmed | 4546 (28·3%) | 13 302 (29·3%) | 226 (30·1%) | 1858 (27·6%)
* |
Infections with symptom assessment | 15 320 (7·5%) | 43 706 (10·8%) | 739 (6·8%) | 4962 (12·3%) | |
Symptomatic infections post-vaccination | 13 682 (6·7%) | 40 354 (10·0%) | 646 (6·0%) | 4575 (11·3%)
* | |
Booster | 98 008 (47·9%)
† | 120 525 (29·7%)
‡ | 0 | 0 | |
Data are n, n (%), mean (SD), or mean (SD); median (IQR). BMI=body-mass index. LFT=lateral flow test.
* Infections during the study period.
† Data indicate that of 204 731 individuals who received two doses of BNT162b2 in the primary immunisation series, 98 008 received a booster dose, including 91 692 who received BNT162b2 and 6316 who received mRNA-1273.
‡ Data indicate that of 405 239 individuals who received two doses of ChAdOx1 nCoV-19 in the primary immunisation series, 120 525 received a booster dose, including 102 780 who received BNT162b2 and 17 745 who received mRNA-1273.
We investigated changes in infection rates after completing the second dose. After the second dose, 62 172 (10·0%) of 620 793 vaccinated individuals and 6726 (16·7%) of 40 345 unvaccinated controls tested positive for SARS-CoV-2 infection. Data were available for up to 8 months after the second dose for BNT162b2, for up to 6 months for ChAdOx1 nCoV-19, and for up to 5 months for mRNA-1273. In line with our previous reports,
23
we observed that 1 month after the second dose, infection risk in the vaccinated group was significantly lower than in the unvaccinated population (vaccine effectiveness of 91·6%, 95% CI 90·7–92·4, for BNT162b2; 83·1%, 82·2–84·0, for ChAdOx1 nCoV-19; and 94·1%, 92·3–95·5, for mRNA-1273), after adjusting for confounders using Poisson regressions
25
(
figure 1,
appendix pp 7–8). As depicted in
figure 1A, vaccine effectiveness gradually started waning after the second shot. BNT162b2 effectiveness was 82·1% (81·3–82·9) at 5 months, 81·6% (80·8–82·4) at 6 months, and 75·7% (73·4–77·7) at 8 months; ChAdOx1 nCoV-19 effectiveness was 75·7% (74·9–76·4) at 5 months and 75·2% (74·3–76·1) at 6 months; and mRNA-1273 effectiveness was 84·3% (81·2–86·9) at 5 months (
appendix pp 7–8).
Figure 1Primary immunisation series effectiveness against infection over time, overall (A) and by age (B) and presence of comorbidities (C)
Show full caption
For each vaccine, we observed a larger waning of effectiveness in individuals aged 55 years or older than in those younger than 55 years, with similar trends observed over time (
figure 1B). For this analysis, we included 300 944 participants who were doubly vaccinated and younger than 55 years, of whom 41 137 (13·7%) tested positive for SARS-CoV-2, and 319 849 aged 55 years or older, of whom 21 035 (6·6%) tested positive. The control group consisted of unvaccinated participants: 34 355 younger than 55 years, of whom 5992 (17·4%) tested positive, and 5990 aged 55 years or older, of whom 734 (12·3%) tested positive.
At 5 months, BNT162b2 vaccine effectiveness was 76·3% (74·0–78·5) in those aged 55 years or older compared with 83·0% (82·0–83·8) in those younger than 55 years; at the same timepoint, ChAdOx1 nCoV-19 effectiveness was 67·8% (65·1–70·2) in those aged 55 years or older compared with 76·7% (75·9–77·6) in those younger than 55 years.
We found that individuals with comorbidities who received the BNT162b2 or ChAdOx1 nCoV-19 vaccine had lower vaccine effectiveness than individuals without comorbidities (eg, 77·5%, 74·9–79·9,
vs 82·8%, 81·9–83·6, at 5 months with BNT162b2; and 70·8%, 68·0–73·5,
vs 76·1%, 75·3–76·9, at 5 months with ChAdOx1 nCoV-19;
figure 1C). For this analysis, 512 431 participants without comorbidities who were doubly vaccinated (52 058 [10·2%] tested positive) were compared with 36 387 unvaccinated individuals with no comorbidities (6106 [16·8%] tested positive); and 108 362 individuals with at least one comorbidity who were doubly vaccinated (10 114 [9·3%] tested positive) were compared with 3958 unvaccinated individuals with at least one comorbidity (620 [15·7%] tested positive). Because the mRNA-1273 vaccine was offered to younger individuals without comorbidities, we could not do analyses stratified by age or comorbidities.
We did sensitivity analyses in participants who test frequently (ie, health-care workers), those who were previously infected, and those with symptomatic infection; we found that vaccine effectiveness at 5 months was not substantially different in any of these subgroups compared with the main analysis (
appendix p 9). To assess whether loss to follow-up was a source of bias, we compared the characteristics at baseline of individuals who stayed enrolled in the study and reported testing results several months post-vaccination with those of individuals who were lost to follow-up; we found that these groups were broadly similar (
table;
appendix p 10).
Vaccine effectiveness against severe infection and hospitalisation remained high 5–6 months after completion of the primary vaccination series (effectiveness against severe infection of 78·8%, 95% CI 77·1–80·3, and against hospitalisation of 84·1%, 81·0–86·7;
appendix p 11). Moreover, vaccine effectiveness was higher among individuals younger than 55 years (effectiveness against severe infection of 79·2%, 77·4–80·8, and against hospitalisation of 84·3%, 80·7–87·2) than among individuals aged 55 years and older (effectiveness against severe infection of 66·5%, 57·5–73·5, and against hospitalisation of 80·4%, 70·7–86·9;
appendix p 12). As the mRNA-1273 vaccine was offered to the younger age group with less severe infection outcomes, we could not do an analysis of effectiveness against severe illness or hospitalisation separately for this vaccine. For BNT162b2 and ChAdOx1 nCoV-19, vaccine effectiveness estimates were greater in younger than in older individuals (
appendix p 12).
During the study period, 194 472 app users registered receiving booster shots with BNT162b2 and 24 061 with mRNA-1273. We assessed the effectiveness of homologous and heterologous booster doses in 135 932 participants aged 55 years or older who received a booster dose (2123 [1·6%] subsequently infected). For individuals who received a booster, we saw significant increases in effectiveness against infection in 0–3 months post-booster compared with the same time period after the second dose in 33 466 individuals aged 55 years or older doubly vaccinated without a booster (824 [2·5%] subsequently infected;
appendix p 13). This translated to a vaccine effectiveness versus unvaccinated individuals aged 55 years or older of 95·3% (92·3–97·1) for homologous BNT162b2 schedules (n=63 632), 91·0% (89·2–92·5) for those receiving a BNT162b2 booster after two primary ChAdOx1 nCoV-19 doses (n=63 922), 88·8% (84·4–92·0) for those receiving an mRNA-1273 booster after two primary ChAdOx1 nCoV-19 doses (n=6000), and 92·5% (86·0–96·0) for those receiving an mRNA-1273 booster after two primary doses of BNT162b2 (n=2378;
figure 2,
appendix p 13).