Pakistan has registered 180 more coronavirus cases and four deaths during the last 24 hours (Thursday), showed the figures released by the Ministry of Health on Friday morning.

As per the latest NCOC data, with the addition of four more deaths the toll has gone up to 30,359, whereas the number of total infections now stood at 1,524,973 after adding the fresh 180 cases.

During the last 24 hours (Thursday), 29,315 tests were conducted throughout Pakistan whereas the positivity ratio stood at 0.61 percent. The number of patients in critical care was 403.

https://twitter.com/OfficialNcoc/status/1509743278379479052 

During the last 24 hours (Thursday), as many as 189 patients have recovered from the virus whereas the total recoveries stood at 1,485,924. As of Friday, the total count of active cases in the country was recorded at 8,690.

As many as 575,331 coronavirus cases have so far been confirmed in Sindh, 505,054 in Punjab, 219,026 in Khyber Pakhtunkhwa, 135,075 in Islamabad, 35,474 in Balochistan, 43,269 in Azad Kashmir and 11,708 in Gilgit-Baltistan.

As many as 13,557 individuals have lost their lives to the pandemic in Punjab so far, 8,097 in Sindh, 6,321 in KP, 1,023 in Islamabad, 792 in Azad Kashmir, 378 in Balochistan and 191 in Gilgit Baltistan.

'Hybrid immunity' gives best Covid protection: studies

People with the "hybrid immunity" of having been both fully vaccinated and previously infected with Covid-19 have the strongest protection against the virus, two new studies said on Friday.

After two years of a pandemic that has seen nearly 500 million people infected and billions vaccinated, the studies highlighted the importance of getting jabbed for those who have natural immunity after recovering from the disease.

One of the two studies published in The Lancet Infectious Diseases medical journal analysed the health data of more than 200,000 people in 2020 and 2021 in hard-hit Brazil, which has the world's second-largest Covid death toll.

It found that for people who have already had Covid, Pfizer and AstraZeneca's vaccines offered 90 percent effectiveness against hospitalisation and death, China's CoronaVac had 81 percent and Johnson & Johnson's one-shot jab had 58 percent.

"All four of these vaccines have proven to provide significant extra protection for those with a previous Covid-19 infection," said study author Julio Croda of the Federal University of Mato Grosso do Sul.

"Hybrid immunity due to exposure to natural infection and vaccination is likely to be the norm globally and might provide long-term protection even against emerging variants," Pramod Kumar Garg of India's Translational Health Science and Technology Institute said in a comment piece linked to the study.

A study using Sweden's nationwide register up to October 2021 meanwhile found that people who recovered from Covid retained a high level of protection against re-infection for up to 20 months.

And people with two-vaccine-dose hybrid immunity had a further 66 percent lower risk of re-infection than those with just natural immunity.

Paul Hunter, a professor in medicine at the University of East Anglia who was not involved in the study, told AFP that the 20 months of "very good protection" from natural immunity was "far better than we would expect for the original two-dose vaccine schedule".

But he cautioned that both studies were completed before the Omicron variant became dominant across the world, and that it had "notably dropped the protective value of a prior infection".

A study in Qatar published on the medRxiv pre-publication website last week gave an insight into the protection offered by hybrid immunity against Omicron.

It found that three vaccine doses had 52 percent effectiveness against symptomatic infection of the BA.2 Omicron subvariant -- but that number jumped to 77 percent when the patient had been previously infected.

The study, which has not been peer reviewed, found that "hybrid immunity resulting from prior infection and recent booster vaccination confers the strongest protection" against both the BA.1 and BA.2 subvariants.

CIA director tests positive

CIA Director William Burns tested positive for Covid-19 on Thursday, a day after meeting with President Joe Biden, the intelligence agency said.

Burns wore an N-95 mask at his meeting with the president and practiced social distancing, it added.

"Their interaction is not considered close contact as defined by CDC guidance, and Director Burns is sharing the news of his positive test out of an abundance of transparency," the CIA said in a statement.

Burns, 65, was fully vaccinated and boosted against Covid and tested positive in a routine PCR test.

He is experiencing mild symptoms and plans to work from home, returning to the office once he has isolated for five days and tested negative.

Biden, at 79 the oldest person to hold the US presidency, got a second booster shot on Wednesday.

Despite strict precautions at the White House, several people who interact with Biden or been close to him have recently tested positive for the coronavirus, raising concerns for his health.

Biden got the extra booster a day after regulators authorized a fourth dose of either the Pfizer-BioNTech or Moderna vaccines for people 50 and older, as authorities warn of a possible new wave driven by the BA.2 variant.

With inputs from AFP.