2/15—New US variant, UK mutation, and studies of allergic reactions after vaccine
Emergence of a Novel SARS-CoV-2 Variant in Southern California
Of 2311 samples, 192 were selected and 185 underwent phylogenetic analysis. The larger cluster (36%, 67 of 185) consisted of a novel variant descended from cluster 20C, defined by 5 mutations (ORF1a: I4205V, ORF1b: D1183Y, S: S13I; W152C; L452R) and designated CAL.20C (20C/S:452R; /B.1.429). Analysis of 10 431 samples from California, including 4829 from Southern California, revealed that CAL.20C was first observed in July 2020 in 1 of 1247 samples from Los Angeles County and not detected in Southern California again until October. Since then, this variant’s prevalence has increased in California state and Southern California, where on January 22, 2021, it accounted for 35% (86 of 247) and 44% (37 of 85) of all samples collected in January, respectively. As clinical outcomes have yet to be established, the functional effect of this strain regarding infectivity and disease severity remains uncertain.
Covid-19: The E484K mutation and the risks it poses
The E484K mutation […] has already been found in the South African (B.1.351) and Brazilian (B.1.1.28) variants. Public Health England confirmed that they have now identified 11 cases of the UK B1.1.7 variant carrying the E484K mutation around the Bristol area and 40 cases of the original SARS-C0V-2 virus carrying the same E484K mutation in the Liverpool area. E484K is called an escape mutation because it helps the virus slip past the body’s immune defences. Ravindra Gupta at the University of Cambridge and colleagues have confirmed that the new B.1.1.7 plus E484K variant substantially increases the amount of serum antibody needed to prevent infection of cells. We already know that the B.1.1.7 variant is more transmissible so a combination of a faster spreading virus that is also better at evading immunity is worrying—if it isn’t stopped it would outcompete the older B.1.1.7 variant.
Necessity of 2 Doses of the Pfizer and Moderna COVID-19 Vaccines
Arguments have been made that because COVID-19 is such a serious disease that is rapidly spreading throughout the world and because vaccines can be made and delivered at a relatively slow rate, a first dose should be given and the second dose delayed until a large amount of the population receives the first dose. It is known that the immune response to 1 dose of the vaccine is relatively weak, even though people who got their first dose had some protection against symptomatic COVID-19 infection. It is not known what will happen if people get only 1 dose. It is possible that people who get only 1 dose will have only partial immunity to COVID-19 infection, resulting in a higher risk that vaccine-resistant variants of SARS-CoV-2, the virus that causes COVID-19, will develop. There is also concern that people who get only 1 dose will think they have sufficient protection against COVID-19 infection and not get a second dose. There is no evidence that people who get only 1 dose have adequate long-term protection against COVID-19 infection.
Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Pfizer-BioNTech COVID-19 Vaccine
During December 14 to 23, 2020, after administration of a reported 1 893 360 first doses of Pfizer-BioNTech COVID-19 vaccine (1 177 527 in women, 648 327 in men, and 67 506 with sex of recipient not reported), CDC identified 21 case reports submitted to the national passive surveillance (spontaneous reporting) system [called “Vaccine Adverse Event Reporting System” or VAERS] that met Brighton Collaboration case definition criteria for anaphylaxis, corresponding to an estimated rate of 11.1 cases per million doses administered. Four patients (19%) were hospitalized (including 3 in intensive care), and 17 (81%) were treated in an emergency department; 20 (95%) are known to have been discharged home or had recovered at the time of the report to the VAERS. No deaths from anaphylaxis were reported. All patients should be instructed to seek immediate medical care if they develop signs or symptoms of an allergic reaction after their observation period ends and they have left the vaccination location.
Reports of Anaphylaxis After Receipt of mRNA COVID-19 Vaccines in the US—December 14, 2020-January 18, 2021
During December 14, 2020 through January 18, 2021, a total of 9 943 247 doses of the Pfizer-BioNTech vaccine and 7 581 429 doses of the Moderna vaccine were reported administered in the US (CDC unpublished data, February 2021). CDC identified 66 case reports received by VAERS that met Brighton Collaboration case definition criteria for anaphylaxis (levels 1, 2 or 3): 47 following Pfizer-BioNTech vaccine, for a reporting rate of 4.7 cases/million doses administered, and 19 following Moderna vaccine, for a reporting rate of 2.5 cases/million doses administered. 32 (48%) were hospitalized (including 18 in intensive care, 7 of whom required endotracheal intubation). No deaths from anaphylaxis after vaccination with either product were reported.