Just four people of 15,601 who received two doses of the COVID-19 vaccine by the end of last week have tested positive for the virus.

And this happened before full immunity was reached, a spokesperson for the health ministry said. The positive tests came between two and eight days after the second jab.

“It should be noted that full immunity of the vaccine is reached after 10 days of taking the second dose,” she said.

The figure, based on data for the week ending February 14, was supplied by the ministry as Malta earlier this week surpassed the 50,000 mark of people who have been given at least one dose.

An additional 149 cases were detected among patients who received only one dose, which conveys about 52 per cent immunity to the virus starting about 10 days later.

No COVID-related deaths have been recorded among those who have been given both doses of the vaccine.

So far, the majority of medical front liners, over 80s and people in homes for the elderly have been given the vaccine.

The health authorities are now in the process of vaccinating non-medical frontliners and those with conditions that make them more vulnerable to complications from COVID-19.

According to public health chief Charmaine Gauci, uptake among the elderly, who were the first to get the vaccine, has been “very high”.

An uptake of around 91 per cent has been registered among healthcare workers.

Malta, together with the rest of EU member states, started administering COVID-19 vaccines on December 27. Preliminary data from a Mater Dei Hospital study shows that the number of people aged over 85 admitted to hospital with COVID has plummeted by about 80 per cent since the start of the vaccination programme.