According to data from the US Centers for Disease Control and Prevention, subtypes BA.4 and BA.5 are driving the surge in Covid-19 cases in the US. The subtypes BA.4 and BA.5 account for 21 percent of the cases in the country.
Since March, 2022, the World Health Organization (WHO) has been monitoring BA.4 and BA.5, which are variants of interest, but Europe calls this a variant of concern, raising concerns that it may be causing another is the driver of the wave. Europe.
“BA.2 is dominant worldwide and BA.2.12.1 is dominant in the US, BA.4 and BA.5 are on the rise around the world,” said Maria Van Kerkhove, Technical for COVID-19 Response at WHO Chief. Week.
What are BA.4 and BA.5?
These are subtypes of Omicron, the fifth edition of the WHO-specified concern. BA.4 and BA.5 were first detected in the US in late March.
Concerns about increase in deaths
“BA.4 and BA.5 are on the rise in many European countries. Portugal suffered a major setback with BA.5, which had a high mortality rate (as high as the first Omicron wave), while their older population was 100 percent vaccinated and increased by almost 100 per cent. Observations in other European countries will show whether this is a continuing trend,” said Dr. Rajeev Jayadevan, a keen observer of the trajectory of the virus and vice-chairman of the research cell, IMA Kerala.
He says it is not only the virus that is rapidly changing, but also our knowledge of vaccination and our immune response to the variants. “The latest paper from Imperial College, published in Science, has revealed some startling and unexpected findings,” says Jayadevan.
The Curious Case of Portugal
Portugal is one of the most vaccinated countries in the world. 100% of the elderly have been vaccinated and almost 100% have received the booster vaccine. However, Portugal’s deaths are higher in 2022 than in 2021 and 2020.
“96% of the entire population has been vaccinated and about 90% have been vaccinated. Mostly, mRNA vaccines are used there and the BA.5 version is included. They also had a huge omicron wave in January and most of the deaths were in older people. It was Jayadevan.
Jayadevan also noted that a study from Japan states that BA.4 and BA.5 cause more lung disease in hamsters than BA.2. “We don’t know if this applies to humans,” he said.
The study being mentioned here was biorxiv. published by And says more lung damage and higher viral loads in the lungs, greater fusogenicity or the ability of the virus to coerce host cells were observed in hamsters.
What is driving the boom in India?
Dr Jayadevan says, “India is witnessing an upsurge mainly because omicron sublines are circulating, people have given up on covid treatment and because we are now several months out of the BA.1/BA.2 wave “
Infectious diseases specialist, Dr Ishwar Gilada says that there are many reasons for the boom in India now. “The current surge in COVID-19 cases globally as well as in some parts of India appears to be due to weakened immunity – natural immunity due to previous infection or due to vaccines, this may lead to an immunity escape in the form of new variants and sub -Variable immunity, greater differences in second and third doses, lack of clarity in policy for a free third dose for populations under 60, no vaccination for children under 12 and under 18 Known for poor speed of vaccination in
Should we anticipate a fatality?
Not yet, say experts.
“BA.4, BA.5 are known to have moderately high replication rates (R0). However, the best thing about the current boom is this trajectory…low oxygen requirements, low bed requirements / Low hospitalization and extremely low mortality. The case fatality rate, which is cumulatively 1.2 per cent for India and 1.87 per cent for Maharashtra, is now barely less than 0.1%,” says Dr. Gilada.
BA.4 and BA.5 are circulating in India but BA.1 and BA.2, which created the third wave in India, still dominate. They account for more than 30 percent of the scenes. The first case of the BA.4 and BA.5 subvariants of the Omicron variant of COVID-19 was first detected in India less than a month ago, on May 22.
Experts say that once BA.4 and BA.5 become effective, cases will see a rise, as both these variants are much more transmissible than other most transmissible BA.2.
“We are much better off in India if we compare elsewhere. The US, Taiwan, North Korea, Brazil and Germany are contributing more than 50% of the weekly cases globally,” Gilada said.
Health economist, Professor Rijo John, is also optimistic. “The reported daily data shows that the current uptick is already losing momentum as the weekly average increase in active cases has started to subside. The rising weekly test positivity has also slowed down. I find this current increase to be very high. Not expecting to see momentum in the immediate term. While caution is always advised, looking at the available data, I don’t see any major concerns at this point of time.” John says.
The Indian Council of Medical Research (ICMR) has also said that barring a rise in cases, it is unlikely that BA.4 and BA.5 can cause a fourth wave in India.
Dr Samiran Panda, Additional Director General, ICMR, told news agency ANI, “To say that the fourth wave is coming, the district-wise data needs to be checked.”
Are the vaccines working?
A study from South Africa showed that people who had previously been infected with Omicron but were not vaccinated experienced an almost eightfold drop in neutralizing antibodies when exposed to BA.4 and BA.5. Experienced.
“Omicron develops mutations to evade the humoral immunity elicited by BA.1 infection, suggesting that BA.1-derived vaccine boosters may not achieve broad-spectrum protection against the newer Omicron forms.” Dr. Sanjeev Bagai, Chairman, visiting the Nephron Clinic.
Europe’s CDC also noted that BA.4 and BA.5 are less efficient and that countries such as Portugal have an increased rate of success infection.
