Safety, immunogenicity, and reactogenicity of BNT162b2 and mRNA-1273 COVID-19 vaccines given as fourth-dose boosters following two doses of ChAdOx1 nCoV-19 or BNT162b2 and a third dose of BNT162b2 (COV-BOOST): a multicentre, blinded, phase 2, randomised trial

BACKGROUND

Some high-income countries have deployed fourth doses of COVID-19 vaccines, but the clinical need, effectiveness, timing, and dose of a fourth dose remain uncertain. We aimed to investigate the safety, reactogenicity, and immunogenicity of fourth-dose boosters against COVID-19.

METHODS

The COV-BOOST trial is a multicentre, blinded, phase 2, randomised controlled trial of seven COVID-19 vaccines given as third-dose boosters at 18 sites in the UK. This sub-study enrolled participants who had received BNT162b2 (Pfizer-BioNTech) as their third dose in COV-BOOST and randomly assigned them (1:1) to receive a fourth dose of either BNT162b2 (30 μg in 0·30 mL; full dose) or mRNA-1273 (Moderna; 50 μg in 0·25 mL; half dose) via intramuscular injection into the upper arm. The computer-generated randomisation list was created by the study statisticians with random block sizes of two or four. Participants and all study staff not delivering the vaccines were masked to treatment allocation. The coprimary outcomes were safety and reactogenicity, and immunogenicity (anti-spike protein IgG titres by ELISA and cellular immune response by ELISpot). We compared immunogenicity at 28 days after the third dose versus 14 days after the fourth dose and at day 0 versus day 14 relative to the fourth dose. Safety and reactogenicity were assessed in the per-protocol population, which comprised all participants who received a fourth-dose booster regardless of their SARS-CoV-2 serostatus. Immunogenicity was primarily analysed in a modified intention-to-treat population comprising seronegative participants who had received a fourth-dose booster and had available endpoint data. This trial is registered with ISRCTN, 73765130, and is ongoing.

FINDINGS

Between Jan 11 and Jan 25, 2022, 166 participants were screened, randomly assigned, and received either full-dose BNT162b2 (n=83) or half-dose mRNA-1273 (n=83) as a fourth dose. The median age of these participants was 70·1 years (IQR 51·6-77·5) and 86 (52%) of 166 participants were female and 80 (48%) were male. The median interval between the third and fourth doses was 208·5 days (IQR 203·3-214·8). Pain was the most common local solicited adverse event and fatigue was the most common systemic solicited adverse event after BNT162b2 or mRNA-1273 booster doses. None of three serious adverse events reported after a fourth dose with BNT162b2 were related to the study vaccine. In the BNT162b2 group, geometric mean anti-spike protein IgG concentration at day 28 after the third dose was 23 325 ELISA laboratory units (ELU)/mL (95% CI 20 030-27 162), which increased to 37 460 ELU/mL (31 996-43 857) at day 14 after the fourth dose, representing a significant fold change (geometric mean 1·59, 95% CI 1·41-1·78). There was a significant increase in geometric mean anti-spike protein IgG concentration from 28 days after the third dose (25 317 ELU/mL, 95% CI 20 996-30 528) to 14 days after a fourth dose of mRNA-1273 (54 936 ELU/mL, 46 826-64 452), with a geometric mean fold change of 2·19 (1·90-2·52). The fold changes in anti-spike protein IgG titres from before (day 0) to after (day 14) the fourth dose were 12·19 (95% CI 10·37-14·32) and 15·90 (12·92-19·58) in the BNT162b2 and mRNA-1273 groups, respectively. T-cell responses were also boosted after the fourth dose (eg, the fold changes for the wild-type variant from before to after the fourth dose were 7·32 [95% CI 3·24-16·54] in the BNT162b2 group and 6·22 [3·90-9·92] in the mRNA-1273 group).

INTERPRETATION

Fourth-dose COVID-19 mRNA booster vaccines are well tolerated and boost cellular and humoral immunity. Peak responses after the fourth dose were similar to, and possibly better than, peak responses after the third dose.

FUNDING

UK Vaccine Task Force and National Institute for Health Research.

Infrainguinal disease treatment: to stent or not to stent

Infrainguinal endovascular interventions have increasingly played a central role in relieving symptoms of claudication and limb salvage over the last decade. Multiple modalities currently exist for treating these arteries; however, balloon angioplasty with or without stenting still remains the most commonly used technique. Despite the concerns regarding the use of stents with stent fractures and in-stent restenosis, there is increased evidence from randomized and non-randomized studies that use of nitinol stents improves patency rates in most patients with >5 cm long lesions. However, the optimal endovascular treatment of the longest lesions is still debated. Infrapopliteal vessels are still mostly treated with balloon angioplasty, but selective use of bare or drug eluting stents especially in longer lesions is promising. The role of drug-eluting stents, balloons and other debulking procedures for both femoropopliteal and infrapopliteal arteries still needs to be further investigated.

Repair of incisional hernias

Incisional hernias develop in up to 11% of surgical abdominal wounds with a possible recurrence following repair of 44%. We describe our experience with a combined fascial and prosthetic mesh repair. Thirty-five patients (16M:19F) have been treated. The original operation was bowel related in 19 cases, gynaecological in 8, hepatopancreaticobiliary in 3 patients, aortic aneurysm repair in 2 and involved a thoraco-laparotomy in 3. The incisions were midline in 26 cases, transverse in 6, paramedian in 2 and rooftop in one patient. The hernias were considered subjectively to be large in 15, medium in 14 and small in 6 of the patients. A proforma was completed for each patient noting intra-operative and post-operative complications, post-operative hospital stay and analgesic requirements. Post-operative complications included seroma formation in 6 patients, deep vein thrombosis in one and a non-fatal pulmonary embolism in another. One patient developed a wound haematoma and one had a superficial wound infection. Post-operative in-hospital stay ranged from 1 to 27 days with a mean of 6.2 days. Of the 35 patients 33 were available for follow-up. Follow-up was for a median of 20.3 months (range 6.0 to 54.1 months). Two of these (6%) patients reported a persistent lump and one (3%) reported persistent pain but none of the remaining 33 was found to have a recurrence. We advocate this technique because it is applicable to all hernias, most of the mesh is behind the rectus sheath and has 2 points of fixation, it is relatively pain-free allowing early mobilisation, has a modest complication rate and a low recurrence rate.

Multidrug resistant typhoid fever: study of an outbreak in Calcutta

Of 103 cases of typhoid fever admitted to the Pediatric Wing of our hospital during the months of August 1989 to April 1990, 82.5% were resistant to chloramphenicol, ampicillin and co-trimoxozole. Nearly 87% children were in the age group of 3-10 years. Fever was present in all and splenomegaly in 90.2% cases. Urinary retention during the course of illness was present in 2 cases. The positivity rate of blood culture, bone marrow culture and Widal test was 83.7, 100 and 13.5%, respectively. Majority of the strains were of Phage 51-Type I. For the treatment of multidrug resistant cases gentamicin and furazolidine proved ineffective. Ciprofloxacin was tried in 85 cases and was found to be effective in all cases with no side effects.

A randomized, controlled comparison of anterior and posterior periocular injection of antibiotic in the prevention of postoperative endophthalmitis

A randomized, controlled, prospective comparison of the effectiveness of anterior and posterior injections of antibiotics in the prevention of endophthalmitis following cataract extraction was carried out in a village hospital in Pakistan. The study involved 77,015 cataract operations performed mainly by two surgeons. Anterior subTenon injections ("subconjunctival") and posterior subTenon injections ("retrobulbar") were equally effective in preventing postoperative infection.

Visual acuity of school entrants

A study of 4239 school entrants showed that 3.4% had less than normal or near normal distant vision and 0.8% had near vision impairment. The group requiring specialist advice and care, that is, those with 6/12 or worse vision in either eye were further investigated. The effectiveness of pre-school examinations in the early detection of vision defects could thus be assessed. The results indicated that two-thirds had not been detected during the pre-school period. Where diagnosed, the great majority were between 3 and 5 years of age. In general, attendance at child health clinics for developmental surveillance was not a significant factor. Given that maturation has an effect, the difficulty seems to be the lack of suitable techniques rather than expertise. This suggests that the whole area of vision testing during the pre-school periods needs to be reviewed.