A laboratory study conducted by researchers affiliated with multiple medical institutions in Germany investigated the surface stability and inactivation profiles of the novel SARS-CoV-2 B.1.1.7 and B.1.351 variants compared to wild type (B.1.1.70) and found comparable susceptibility towards disinfection with heat (56 degree C), soap for 1-5 minutes, and 30% ethanol for 30 seconds (Figure 1). There was also comparable surface stability on steel, silver, copper, and face masks (Figure 2), indicating there was no enhanced surface stability of the variants compared to wild-type. These findings suggest how the current recommended hygiene measures are sufficient to combat the risk of SARS-CoV-2 variant transmission.

A multidisciplinary team of researchers conducted a cohort study to analyze the antibody levels for spike, receptor binding domain (RBD), and virus neutralization after BNT162b2 mRNA vaccination in 149 nursing home (NH) residents (median age 76), 110 healthcare worker controls (median age 48), and 22 unvaccinated recently-infected convalescent controls (median age 53).
NH residents with no prior COVID-19 infection had significantly lower rates of neutralization titers (81% vs 99%), anti-spike levels, and anti-RBD levels than HCW controls. SARS-CoV-2 convalescent subjects had higher antibody titers compared to SARS-CoV-2-naive subjects in all groups. The lower titers among nursing home residents could lead to less protection from infection and suggests a lack of clarity how long any protection could last.

An observational study conducted in Jura, France from March 8, 2021 to March 29, 2021, reported a SARS CoV-2 variant 501Y.V2 outbreak at a nursing home among 31 residents and 59 staff members. 50% (13/26) of vaccinated residents and 100% (5/5) annd non-vaccinated residents were infected. Non-vaccinated residents (80%, 4/5) had more severe disease when compared to vaccinated residents (15%, 2/13). Among staff members, 1 vaccinated (5.2%) and 10 non-vaccinated (25%) were infected with no severe disease development. Although based on a limited sample size, researchers concluded that the BNT162v2 mRNA vaccine (Pfizer) reduces severity and transmission of disease but not necessarily prevents outbreaks of emerging variants. They suggest that instead of relying on vaccine to prevent outbreaks in nursing homes, residential programs should conduct weekly symptom screening and viral testing post vaccination.

An observational cohort study conducted at the Federal University of Pará in Brazil followed 125 anti-SARS-CoV-2 antibody positive volunteers for 90 days following COVID-19 diagnosis to assess the persistence of antibodies. They found that persistence was detected after 90 days in 87 participants (69.6%) (Table 3) with symptoms lasting longer in those with persistent IgG response (greater than or equal to 21 days, compared to less than or equal to 7 days) (Table 2). The findings suggest a potentially high rate of immunity loss in this population.

An international team of researchers shared interim results from a phase 1-2a clinical trial on the efficacy of the Ad26.COV2.S candidate vaccine, a replication-incompetent adenovirus vector encoding a SARS-CoV-2 spike (S) protein, in 403 individuals aged 15-55 (cohort 1) and 402 individuals aged >65 (cohort 3). Both cohorts received a high or low dose of the vaccine in a single-dose or two-dose schedule 56 days apart. The most common adverse reactions included fever, fatigue, headache, myalgia, and injection-site pain, which were more commonly reported in cohort 1 and in those who received the low dose (Figure 1). Neutralizing antibody titers against wild-type SARS-CoV-2 were present in more than 90% of participants on day 29 after the first dose, and a second dose increased titer by a factor of 2.6–2.9 (Figure 2). These findings suggest that the Ad26.COV2.S vaccine is safe and effective in both younger and older adults with minimal side effects.