The rate of infections from the coronavirus is lower than a year ago in southern hemisphere countries which are going into winter, according to scientists.

Margherita Ghiselli, Regional Immunisation Adviser for Public Health of Pan American Health Organisation, shared this information as part of a Facebook Live discussion hosted by the Bermuda Health Council on Thursday.

In a presentation about the future of Covid-19 vaccines, she said: “We have never had, in the northern hemisphere, a winter and vaccines being applied at the same time.”

Coronavirus infections are generally expected to rise in winter and to decline in summer. Southern hemisphere countries are entering winter now.

“What we are doing is examining very closely the situation in Chile, Argentina and Brazil, who are having their winter season right now, to see what is happening.

“It seems that the number of cases does increase although not to the same levels as last year. These countries have launched huge vaccination campaigns against influenza and that is another strategy to free up healthcare space.

“We are collecting data from the southern hemisphere and the situation looks better than last year.”

Dr Ghiselli, who spoke before a question-and-answer session facilitated by Dr Ricky Brathwaite, BHC chief executive, said four different variants of the virus which are currently “of concern” – the Alpha variant which originated in the UK, the Beta from South Africa, the Gamma from Brazil and the Delta from India.

She said there were further “variants of interest” that are being monitored by PAHO which serves as Regional Office for the Americas of the World Health Organisation, the specialised health agency of the United Nations.

“These are the only four of concern that we know of,” she said. “There are variants of interest where we do not yet know if they cause higher transmissibility of more serious disease. We just want to keep an eye on them.

“What we have most in the Americas are the Alpha variant and the Gamma variant. These are the variants that we are monitoring more closely. We are always looking for more variants and we are always monitoring. If there are new variants we make sure to inform the public as soon as possible.”

She said WHO-validated vaccines were working against the variants.

“A number of studies that show, especially against the Alpha variant, all vaccines work pretty well. For Beta and for Gamma too we also have good evidence, not as much as for Alpha.”

She said there had been very little time to study the vaccines’ effectiveness against Delta but that data collected so far suggest AstraZeneca and Sinovac are showing high levels of protection.

She said: “We know that vaccines do protect against these variants of concern. That is very, very encouraging news.”

Dr Ghiselli said it even those who are vaccinated should continue to take public safety measures such as social distancing, mask wearing and regular hand washing.

“We are still learning a lot. We don’t know how long the immunity lasts. We don’t know how well it protects others from receiving the virus from you if you have been vaccinated.

“Then there are variants of concern that, when they come out, we don’t know how the vaccination will work against them.

“Even if you are vaccinated, it is still a very good idea to implement those mitigation measures.”