Just eight months ago, the world seemed to be regaining control from the Sars CoV-2 virus, when a new variant called Omicron entered and began to upset the progress made. It was first found in South Africa and then spread like wildfire. Multiple sub-genres emerged and the world saw wave after wave of BA.1 / BA.1.1 / BA.2 / BA.2.12.1 / BA.2.38 / BA. 2.75 / BA.4 and BA.5 – The list is long and more are being added regularly.
Fortunately, Omicron and its subtypes cause disease that appears to be milder than that caused by the earlier delta mutation. Even so, today we are seeing a gradual rise in hospitalizations and, according to reports this week, deaths are up 39% compared to two months ago. So, what is BA.5 and should we worry (again)?
BA.5 is a subtype of Omicron discovered earlier this year in South Africa, where it caused a significant wave of infections. It has advanced relentlessly and is rapidly replacing other subforms that are dominant in many geographies. The United States (US), for example, reports that BA.5 accounts for nearly 80% of all new cases. Europe is stabilizing after the wave caused by BA.5 last month.
The Omicron mutation is notable for having more than 50 new mutations that scientists had never seen or expected before. BA.5 goes even further with three major mutations in its spike protein, which help it remain disguised by the immune system and lead to infections. These mutations lead to a phenomenon called immune evasion. BA.5 has acquired the ability to evade antibodies produced after vaccination, about three to four times more efficiently than previous strains. Also, vaccine protection is fading in many countries due to inappropriate booster uptake. Thus, the number of infected people is increasing.
Also, antibodies induced by previous infections with delta or older omicron subvariants no longer provide persistent protection, and re-infection appears to be more frequent. An understanding of how prevalent BA.5 can be can be seen from US data. In early June, BA.5 accounted for less than 10% of cases. By the end of July, BA.5 accounted for 79% of all cases. And the resurgence of global travel and the relaxation of mask orders won’t help.
With home testing becoming easier to administer and results often going unreported, it’s important to remember that the actual numbers are higher than the announced numbers. Some reports put the underreporting ratio at 1:7. The symptomatology of Covid-19 has changed with Omicron. Common symptoms with BA.5 are extreme fatigue, runny nose, sore throat, persistent cough and headache. Loss of taste and smell is not evident. Fortunately, most symptoms require outpatient care.
Hospitalization numbers with BA.5 are higher than with previous Omicron subvariants because of the sheer volume of people infected. Globally, deaths attributable to Covid-19 have gradually increased to an average of 2,200 deaths per day. The time taken for a person with BA.5 to test negative is extended to about 10 days. Therefore, after seven days of isolation, it is essential to follow the recommendation of masking for the next seven days. Its implications can be worrisome. Each re-infection, even if asymptomatic, predisposes the individual to a higher risk of complications such as cardiovascular diseases, diabetes, organ damage and cognitive decline. And the risk of chronic Covid-19 remains, with symptoms persisting for months after infection.
The revival due to BA.5 has important ramifications for corporate organizations and employers worldwide, who recently started calling their employees back to the office. With increased transmission, re-infection, declining vaccine coverage and threats of new public health emergencies such as monkeypox, the risk to the health of the workforce has increased. Now, more than ever, there is a need for a formal contingency plan based on reliable health updates and sound medical guidance. Employees, whether in offices or working remotely, should have access to reliable health advice and interventions.
BA.5 will certainly not be the last. There are many variants, some benign and some malignant. An epidemic is not far away. It’s time to get your vaccine booster, cover up and stay masked.
The article was written by Dr Vikram Vora, Medical Director of India International SOS, a leading health and security services group.