Brazil has warned women to postpone pregnancy until the worst of the coronavirus pandemic has passed, saying that the variants of the coronavirus in Brazil have been more aggressive in pregnant women.

"If possible, (the women should) postpone the pregnancy a bit to a better time so that (they) can have a more peaceful pregnancy," Secretary of Primary Health Care of the Brazilian health ministry Raphael Camara said Friday.

"We cannot say this to those who are 42, 43 years old, of course, but for a young woman who can, the best thing is to wait for a little," he said during a press conference.

Brazil is second only to the US in terms of Covid-19 deaths, according to Johns Hopkins University, with 368,749 deaths and more than 13.8 million cases.

Cities across the country have been hit hard by a recent surge in Covid-19 cases and deaths, fueled in part by new variants believed to be extra contagious and some Brazilians' disregard for social distancing precautions.

The country could be headed for even worse times thanks to a combination of political chaos and inaction, a team of public health experts warned this week.

"In Brazil, the federal response has been a dangerous combination of inaction and wrongdoing, including the promotion of chloroquine as treatment despite a lack of evidence," a team led by Marcia Castro of the Harvard T. H. Chan School of Public Health, experts at the University of São Paulo and elsewhere wrote in their report, published in the journal Science.

Researchers argued that "prompt and equitable" responses from the federal government could have helped contain the outbreak and protect the most vulnerable -- but leaders have failed, and are still failing, to do so.

In the city of Manaus, a spike in severe cases led to hospital systems collapsing, with a shortage of oxygen for patients."

Without immediate action, this could be a preview of what is yet to happen in other localities in Brazil," the team warned. Unless the government took immediate action, conducted epidemiological and genomic surveillance measures, and stepped up vaccinations, the spread of variants will likely lead to "unimaginable loss of lives." Camara said Friday that the ministry is working on studies on the issue of pregnancy and variants.

"We do not have a national or international study, but the clinical view of experts shows that the new variant has a more aggressive action on pregnant women," he said. "Before, [severity] was linked to the end of the pregnancy, but now (they) see a more serious evolution in the second trimester and even in the first trimester," he added.

Pregnant women in UK can get jab

Meanwhile, the UK's vaccine advisers said pregnant women "of any age" in the country can be offered either the Pfizer/BioNTech or Moderna Covid-19 vaccines."

Although clinical trials on the use of Covid-19 vaccines during pregnancy are not advanced, the available data do not indicate any harm to pregnancy,"

Friday's updated guidance said. "JCVI [The Joint Committee on Vaccination and Immunisation] has therefore advised that women who are pregnant should be offered vaccination at the same time as non-pregnant women, based on their age and clinical risk group."

The guidance further said that "there is now extensive post-marketing experience of the use of the Pfizer/BioNTech and Moderna vaccines in the USA with no safety signals so far. These vaccines are therefore the preferred vaccines to offer to pregnant women."

"Pregnant women who commenced vaccination with AstraZeneca, however, are advised to complete with the same vaccine."