After a lull around the globe Covid variants seem to be returning. Though this was expected to be worse in winter, nobody could predict the variation in mutation. Since Omicron emerged in late 2021, it has rapidly evolved into multiple subvariants. One such subvariant, BE.7, has been recently identified as the main variant spreading in China. Though reports from China regarding the variant is concerning, it doesn’t appear to be growing too much elsewhere in the world.BF.7 is a sub variant of BA 5, Most disturbing fact about this variant is the most infectious of al variants and being quicker to transmit, has a shorter incubation period, and has a greater capacity to infect people who has had previous COVID infection, or has been vaccinated, or both.
This ability to evade the immune system is scary. BF.7 is believed to have an RO (reproduction number) 10 to 19. This means an infected person can transmit to 10 to 18 people whereas Omicron had an average RO of 5. The symptoms of BF.7 are like those associated with other Omicron variants. Upper respiratory symptoms with fever, cough, sore throat, runny nose and fatigue are common. A few may have gastrointestinal symptoms of diarrhea and vomiting. BF carries a specific mutation, R346T, in the spike protein of SARS-CO-2. This mutation was also seen in the parent variant BA.5. A recent study examined the neutralization of BF.7 in sera from triple- vaccinated healthcare workers, as well as patients infected with Omicron BA.1 and BA.5 waves of the pandemic. BF.7 was resistant to neutralization.
This is not very encouraging. Bf.7 has already been detected around the world including India, US, UK and several other European countries. The silver lining is that this variant seems to be remaining steady elsewhere other than in China. In fact in USA the percentage of B7 variant infection decreased from 6.6% in early December to 6.3%.There are many theories floated for this like may be because of Zero COVID policy of China and due to low vaccination uptake the herd immunity may be low. In testing for these variants , early data suggests that antigen tests do detect the Omicron variant but may have reduced sensitivity. So the recommendation of FDA is to repeat the antigen test if one is symptomatic. FDA has listed tests that are impacted by this new variant.
Vaccine still remains the main stay of protection. Recent approval of U.K for the bi-valent vaccine is welcoming news increasing the confidence level in vaccination. More than 5.4 billion people worldwide have received a dose of Covid 19 vaccine, equal to about 71.3% of world population. The uptake varies from 99% in Samoa to 0.2% in Burundi. In India about 70% of population has received at least one of the vaccine. A nasal COVID 19 vaccine based on technology licensed from Washington University in St.Louis has been approved for emergency use in India. The main advantage of the nasal vaccine other than it doesn’t need a needle- is that it triggers an immune response in the nose and upper airway right where the virus enters the body. In doing so the potential to block the infection and break the cycle of transmission.
The technology transfer was done to Baharat Biotech based on about 3100 people who participated on a clinical trial in India. This vaccine can be administered both as a primary vaccine or as a booster. What we need is a universal vaccine to cover all the variants.
Unlike the Biblical prodigal son the world is not going to celebrate the arrival of the prodigal son. People will have to still practice caution of testing, treating and tracking to keep the endemicity low. World will wait anxiously for winter to end by when season of other cold viruses at least will decrease.
