UK infections continue upwards
https://health-study.joinzoe.com/data
Reinfections now common
https://www.independent.co.uk/news/health/covid-omicron-reinfection-symptoms-uk-cases-b2115027.html
https://www.science.org/doi/10.1126/science.abq1841
Generally, infections tend to milder the second or third time round
Danny Altmann, professor of immunology, Imperial College London
Omicron is poorly immunogenic, which means that catching it offers little extra protection against catching it again
Prof Tim Spector
There are definitely a lot of people who got Covid at the start of the year who are getting it again,
including some with BA.4/5 who had BA.1/2 just four months ago
rare to be reinfected with within three months
BA.2.12.1, BA.4 and BA.5 escape antibodies elicited by Omicron infection
https://www.nature.com/articles/s41586-022-04980-y?utm_medium=affiliate&utm_source=commission_junction&utm_campaign=CONR_PF018_ECOM_GL_PHSS_ALWYS_PRODUCT&utm_content=textlink&utm_term=PID100062364&CJEVENT=e070b984fbde11ec819046bd0a180514
New sub-variants notably evade the neutralising antibodies elicited by SARS-CoV-2 infection and vaccination
Vaccine boosters based on the BA.1 virus
(e.g. those developed by Pfizer/BioNTech and Moderna)
may not achieve broad-spectrum protection against new Omicron variants
Dr. Onyema Ogbuagu, Yale School of Medicine, Connecticut
My personal bias is that while there may be some advantage to having an Omicron-specific vaccine,
I think it will be of marginal benefit over staying current with the existing vaccines and boosters
Despite immune evasion, the expectation can be that vaccines will still protect against serious disease
What we’ve learned clinically is that it’s most important to stay up-to-date with vaccines
to maintain high levels of COVID-19 antibodies circulating in the blood
Kei Sato, University of Tokyo
New sub-variants may have evolved to refavour infection of lung cells
Risk is potentially greater than that of original BA.2
Dr Stephen Griffin, University of Leeds
It looks as though these things are switching back to the more dangerous form of infection, so going lower down in the lung
Neutralization Escape by SARS-CoV-2 Omicron Subvariants BA.2.12.1, BA.4, and BA.5
https://www.nejm.org/doi/full/10.1056/NEJMc2206576
Subvariants BA.1 and BA.2, substantial escape from neutralizing antibodies
Subvariants BA.4 and BA.5 have identical sequences of spike protein
Comparison of neutralizing antibody titer WA1/2020 isolate with BA.1, BA.2, BA.2.12.1, and BA.4 or BA.5
Isolate USA-WA1/2020 from an oropharyngeal swab,
returned from China,
who and developed clinical disease,
January 2020 in Washington, USA
In 27 participants, all vaccinated and boosted with Pfizer,
And 27 participants who had been infected with the BA.1 or BA.2 median 29 days earlier (range, 2 to 113 days)
In the vaccine cohort
Participants were excluded,
if they had a history of SARS-CoV-2 infection,
or a positive result on nucleocapsid serologic analysis,
or if they had received another covid vaccine,
or an immunosuppressive medication
Six months after the initial two BNT162b2 immunizations
Neutralizing antibody titer against WA1/2020 = 124
Neutralizing antibody titer against omicron subvarients = 20
Two weeks after administration of the booster dose
Neutralizing antibody titer against WA1/2020 = 5,783
Neutralizing antibody titer against BA.1 = 900
BA.2 = 892
BA.2.12.1 = 410
BA.4 or BA.5 = 275 (21 times lower than 5,783)
What about natural immunity
Among the participants who had been infected with BA.1 or BA.2,
26 had been vaccinated
Median neutralizing antibody titer
WA1/2020 isolate = 11,050
BA.1 = 1,740
BA.2 = 1,910
BA.2.12.1 = 1,150
BA.4 or BA.5 = 590 (18.7 times less than 11,050)
These data show that the BA.2.12.1, BA.4, and BA.5 subvariants substantially escape neutralizing antibodies induced by both vaccination and infection.
SARS-CoV-2 omicron variant has continued to evolve with increasing neutralization escape.
These findings provide immunologic context for the current surges caused by the BA.2.12.1, BA.4, and BA.5 subvariants,
in populations with high frequencies of vaccination and BA.1 or BA.2 infection.
