The past few weeks saw the emergence of a surreptitious subvariant of the Omicron variant of the SARS-CoV-2 virus, which experts called “stealth.”
Stealth, often synonymous to sneaky, was used to describe this sub-lineage called BA.2 since its genetic mutations are harder to differentiate from the deadly Delta variant. And since BA.2 is Omicron, it has been declared a variant of concern as well by the World Health Organization (WHO).
The recent “Stop Covid Deaths” webinar on Covid-19 organized by the University of the Philippines together with UP Manila NIH National Telehealth Center and UP-Philippine General Hospital, featured a number of international speakers led by Dr. Martin Hibberd, a Professor on Emerging Infectious Diseases Department of Pathogen Molecular Biology of the London School of Hygiene and Tropical Medicine to talk about this new subvariant.
He said the virus that is most numerous is Omicron, which appeared at a very early stage during the virus evolution, even before March 2020. This means that this variant has long been in the background and is starting to suddenly expand only now. “This virus is not very good at transmitting but suddenly acquired a new set of mutations that generated a more transmissible variant, and the variations happened in a rush.”
He emphasized that more testing has allowed a more accurate estimation of the number of infections. Citing the case of the virus in the United Kingdom, by the looks of it, Dr. Hibberd said the Omicron is spreading much more than the original Wuhan or the Alpha strain.
However, when compared with the other strains, Omicron had the higher number of cases compared to Alpha and Delta, but had fewer hospitalizations and even deaths than Alpha. “However, we had less deaths in Delta that time due to lockdowns and we had effective vaccines where recently, we vaccinated more than a million people a day with the booster doses,” Dr. Hibberd emphasized.
Right now, Dr. Hibberd said the UK is going with its third booster dose because of what Omicron’s immune escape can do, citing tests in the UK that showed Omicron is most likely to re-infect more than Delta.
As to whether the world will shift from pandemic to endemic stage, Dr. Hibberd said that Covid-19 is a nasty disease that is here to stay because it is so widespread globally, in humans and also in animals. He also predicted that it was likely that new variants would emerge every year and that these should be monitored in the same way as influenza. “With influenza, we take a sample of the dose and make a new vaccine each year, which protects vulnerable people from a new influenza strain, and we have to do that with Covid-19 as well.”
Vaccination also needs to be updated every year, hoping that a new, longer lasting and broader response vaccines are on the way. The good news, Dr. Hibberd said, is that there are now direct, anti-viral therapies that will offer help to people who are not yet vaccinated, or who got the disease despite vaccination. “To make the most of those, we need to test, find out early and treat patients early.”
For Dr. Hsu Li Yang, Vice Dean for Global Health and Program Leader for Infectious Diseases at the Saw Swee Hock School of Public Health at the National University of Singapore, he said the first Omicron case was discovered in December 2021, with Omicron BA.2 cases happening by January 2022. Between January 2022 up to now, the number of BA.2 cases has jumped by over 50 percent.
Dr. Hsu noted that with all their strategies in facing Covid-19, what would be the way forward? He said they realized they cannot keep the virus from affecting the economy and they have done their best to protect the population by encouraging people to be vaccinated. “We are still one of the very few countries that have not relaxed restrictions; we don’t think that would change yet. But everyone is now looking forward to seeing the restrictions removed and reintegrate with the rest of the world again in the future.”
On the other hand, Dr. Cynthia Saloma, Executive Director of the Philippine Genome Center, she said the earliest Omicron (BA.1) was detected in December 22, while the earliest BA.2 was a local case detected in Mindanao. With the rapid rise in cases, Omicron eventually overtook Delta as the dominant variant at the beginning of 2022.
Peak in Omicron cases
However, Dr. Saloma said it seems the country has reached its peak in Omicron, since we are earlier than some of the country’s Asian neighbors in terms of having Omicron cases with a rapid rise that peaked in Week 2 of January with about 39,000 cases but rapidly declined to about 2,000 at present.
She also credited the move to vaccinate people, the medical frontliners and the vulnerable sectors starting March of last year. “Although we had more cases with Omicron, the number of deaths were lower because of vaccination.”
In the case of the Philippines, Dr. Saloma noted that 98 percent are under Omicron BA.2 sublineage. Globally, she said there is observed increase in the proportion of BA.2 but as BA.2 sees a rise in percentage share in Omicron cases, it is still overshadowed by the BA.1 and even its subcluster BA.1.1. She said, however, that Returning Overseas Filipinos (ROFs), including some international travelers, bring the BA.1 sublineage. “But what we observed in our community transmission was BA.2, which is why it is also part of the reason why the country opened its borders because the transmission of the virus is not so much because of fresh introduction events from the airport but it’s really driven by local community transmission of BA.2.”
So, will Omicron be the last of the variants? Is it the endgame for this pandemic? Probably not, Dr. Saloma said, because the virus continues to mutate and that other variants will continue to emerge but will these be more transmissible, will they be more severe, or could they mutate to a more benign form, or mutate with other symptoms? “These we don’t know yet but some experts say the pandemic is already on an evolutionary decline, a slide towards endemism where the virus and humans co-exist. This coronavirus continues to surprise us, and we’re not really sure how this pandemic will play out. What’s important is we continue to monitor and be vigilant and not put our guards down.”
(This article, written by Rory Visco, was first published in the Business Mirror Website on February 23, 2022)