The third Omicron wave has begun and is expected to grow rapidly and peak in August, says a COVID model expert. “I think there was hope that we wouldn’t have another surge until the fall, but the surge is starting now,” said Sally Otto, who advises masking again, along with getting booster shots. Otto, an evolutionary biologist and mathematical modeler at the University of British Columbia, presented her data at the main meeting of North American Evolutionary Biologists in Cleveland, Ohio, last week. Data from public health laboratories across Canada monitoring the Omicron BA.4 and BA.5 subvariants show that they will soon overtake the original Omicron subvariants in Canada, said Otto, who is part of the COVID-19 modeling team at P. X. “Right now we’re at a reasonable low point, the low point in 2022,” Otto said in an interview. “So we can afford to be a little bit more relaxed right now, but not for long because this is growing so fast that we’re going to face more risk. “Go to the grocery store now and your risk is pretty low. Go to the grocery store in three weeks and there’s a good chance someone else will have COVID.” Much uncertainty remains about the severity and harmfulness of subvariables BA.1 to BA.5, Otto said — at a time when public health measures are at their lowest level since the pandemic, with no mask mandate, no provincial proof vaccination requirement for public events and gatherings and little appetite to bring them back. “Every week in July that goes by, the risk of COVID doubles, and this will help people understand how much more likely they are to experience COVID in their communities,” Otto said. “But the good news is it’s summer, so have those outdoor parties and open those windows and just avoid those crowded places with strangers as much as possible — and wear a mask — but don’t stop living.” Otto recommends wearing a mask in crowded indoor environments, “especially by mid-July and August when this next wave of cases will be in full swing.” It also encourages those who qualify to get their COVID-19 boosters before the peak of the BA.4 and BA.5 wave and not wait for newer vaccines. Last week, the National Immunization Advisory Committee recommended booster shots before a drop wave for people age 65 and older, people in long-term care, people with clinical immunity, Indigenous people and marginalized communities. NACI said it will provide recommendations on the type of vaccine for COVID-19 as evidence becomes available on appropriate vaccines. Otto said she cannot predict whether there will be a fallout wave or its expected virulence. “What I can say is that there is still enormous evolutionary potential for this virus because there are so many cases worldwide, and that means this virus is changing in many ways around the world,” Otto said. “I think that COVID is with us for the long term and we need to get better at reacting and responding – when the waves rise, so do all the protection measures, and when the waves fall, as we are now, to a reasonable low point … we can afford to be a little more relaxed … but not for long.” For those losing track of variants and sub-variants, COVID-19 mutated into Alpha, Beta, Gamma, Delta and Omicron variants. Omicron is considered less lethal than Delta but more contagious. The Omicron BA.4 and BA.5 subvariants are similar to the original Omicron BA.2 subvariant, with the exception of some mutations. “And these mutations make BA.4 and BA.5 even more difficult for our immune system to recognize the virus,” Otto said. Several countries, including the US, Portugal, France, Israel and Italy, have reported an increase in COVID-19 cases. Canada’s public health chief Theresa Tam issued a statement Thursday saying the BA.4 and BA.5 subvariants are more contagious and can evade immunity better than earlier versions. An increase in cases is likely in the coming weeks, he said. As of June 18, there were an estimated 15,047 new weekly cases of COVID-19 in Canada, comparable to November and down from 288,771 cases per week at the peak of the Omicron wave in January. While numbers of BA.1 and BA.2 Omicron COVID-19 subvariants are declining, estimated numbers of BA.4 and BA.5 are increasing at a daily growth rate of 3.1 percent in British Columbia. By comparison in Alberta the growth rate is 4.9 per cent, doubling every 14 days, 6.3 per cent in Ontario doubling every 11 days and 5.5 per cent in Quebec, doubling every 12 days. The good news is that data from the COVID-19 Immunity Task Force and Canadian Blood Services suggest high levels of antibodies in all age groups, as determined through blood donation by mid-May. The bad news is that the antibodies’ ability to neutralize the COVID virus and prevent infection is essentially compromised for the BA.4 and BA.5 subvariants, Otto said. [email protected]
To comment on this article, write a letter to the editor: [email protected]
