The Pan-American Health Organization (PAHO) and the World Health Organization recommend an R number of one or less than one, and a positivity rate of less than four per cent for COVID-19.
Chairman of Cabinet’s COVID-19 Sub-committee and Minister of Foreign Affairs and Foreign Trade, Senator Dr. Jerome Walcott, stated this today during a press conference at Ilaro Court, and gave an explanation of the terms R number and positivity rate.
“The R number is simply a tool used by epidemiologists that gives a rating to infectious organisms, for example coronavirus, in terms of the ability of that disease to spread in a society. That is, if one person is infected with coronavirus how many persons is he likely to transmit that to in a population that is susceptible,” he explained.
Using the example of measles, Senator Walcott said the R number for measles is 15. He stated that in a country where there is no immunisation against measles, that means if one person is infected with measles, that person could essentially spread measles to 15 persons and those 15 persons could potentially spread it to 15.
Minister Walcott pointed out that based on coronavirus modelling, scientists had worked out that the R rate number is three. “If I have the disease, I could spread it to three persons in a room, and both persons, once they’ve contracted it, can then pass it on to three persons,” he explained.
He noted that the aim is to have an R number of one, or less than one. “In terms of the modelling being done now, they see that our R factor is about 1.4, which means that it can spread in the society; it is a susceptible society. And all the more reasons why people must adhere to the protocols which are very important; the wearing of mask, hand sanitising and your physical distancing,” Senator Walcott stated.
The Chairman of Cabinet’s COVID-19 Sub-committee said in terms of the positivity rate “that is a simple matter of the number of positive tests over the total number of tests and a percentage of that. And ideally, you aim for a percentage of perhaps less than four per cent”.
Meanwhile, Prime Minister Mia Amor Mottley stressed it is important for persons in the country to get vaccinated in order to bring down its susceptible population.
“Our susceptible adult population is anywhere around 210,000 to 220,000, once we take out the people under 18, we can reduce that through vaccination to less than 100,000 to 50,000 even,” she stated.
The Prime Minister noted that if the country did not have any COVID-19 protocols in place, the R number would probably be at least three, and Government’s aim is to bring the island’s rate under one or as close to zero as possible, but in order for that to happen, herd immunity must be obtained through vaccination.
“And, we need now to recognise that this is part and parcel of the strategy to be able to bring down the R number,” she said.
Ms. Mottley stressed that Government was working day and night to procure vaccines not only for citizens of Barbados, but anyone who is residing in the country, including those in the Welcome Stamp Programme.