Washington – The Pan American Health Organisation (PAHO) says a group of experts has recommended the continued genomic surveillance in the Americas, including the Caribbean, to detect any unusual or unexpected increase in cases, increase in lethality or change in clinical patterns that could affect control measures, including vaccines, for variants of the SARS-CoV-2, the virus that causes coronavirus (COVID-19).
During a webinar for journalists, PAHO said its experts, as well as those from the Oswaldo Cruz Foundation (Fiocruz), discussed key questions raised by the variants, including their impact on transmissibility, the severity of COVID-19 and the effectiveness of vaccines against them.
“Mutations are expected in the virus evolution and adaptation process,” said Dr Jairo Mendez Rico, PAHO’s advisor on emerging viral diseases. “When these variants have a potential impact or risk for public health, they are considered variants of concern (VOC).”
PAHO said the four variants of concern that have been detected in the Americas include those that originated in the United Kingdom (B 1.1.7), South Africa (B.1.351), Brazil (P.1) and India (B.1.617).
So far, PAHO said 37 countries and territories have confirmed the presence of one or more of the four variants of concern.
It said variant B.1.1.7 was confirmed in 34 countries; variant B.1.351 in 17, variant P.1 in 21 countries, and variant B.1.617 in eight countries.
“The occurrence of mutations is a natural and expected event within the evolutionary process of the virus,” Mendez said. “These changes could lead to advantages for the virus to achieve its ‘objectives’, which are to have a better capacity to enter the cells and then to replicate, and to try to escape the immune response, either natural or vaccine-mediated.”
He, however, added: “Although some [variants of concern] have demonstrated enhanced capacity to replicate and transmit, they are not more aggressive or severe.”
He pointed out that, from an evolutionary perspective, “it is not in the virus’ interest to kill its host.”
Mendez also said that “so far, there is not sufficient evidence to infer that currently available vaccines do not work with these variants”.
PAHO said the higher the transmission level within populations, the more likely it is that viral mutations will occur.
“The experts agreed that slowing or halting transmission is the only way to avoid the appearance of new variants,” PAHO said.
“They recommend maintaining all public health measures where the virus is circulating, regardless of the variants.”
These include using face masks, maintaining physical distancing from others, avoiding crowded, closed spaces, opening windows for ventilation, hand hygiene and getting vaccinated when vaccines become available, PAHO said.
It said the experts also recommended strengthening both epidemiological and genomic surveillance to reduce the spread of the virus and possible mutations.
PAHO said that when the COVID-19 pandemic began in 2020, it set up the COVID-19 Genomic Surveillance Regional Network to strengthen the sequencing capacity in participating laboratories in the Americas, and to establish routine SARS-CoV-2 genomic sequencing.
The network in the Americas was significantly expanded to identify and track variants of the SARS-CoV-2 virus, PAHO said.
It said 22 countries are now participating in the network, “giving a much better picture of the variants circulating in our region”.
According to PAHO, countries in the Americas first began using genomic surveillance during outbreaks of cholera years ago, adding that this continued with outbreaks of influenza, chikungunya, Zika and yellow fever.
Dr Sylvain Aldighieri, COVID-19 Incident Manager at PAHO, said it is vital to keep genomic and epidemiological surveillance coordinated “to detect any unusual or unexpected increase in cases, increase in lethality or change in clinical patterns, because these aspects may be associated with a particular variant.
“This is why collaboration and information exchange between countries is extremely important,” he said.
(CMC)
