London, Jan. 10, 2021(AltAfrica)-A nurse in Wales, a country in United kingdom caught Covid three weeks after getting the vaccine, prompting warnings from experts that it takes time for immunity to build up.

The nurse, who has been working for the Hywel Dda University Health Board area, said that she contracted the virus while waiting for the second dose of the Pfizer-BioNtech jab.

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The woman, who did not wish to be identified, said she was ‘angry and heartbroken’ to have caught Covid at this stage. 

She said she was ‘initially relieved’ to have been offered an appointment and wanted to do the right thing for her family.   ‘But it gives a false sense of security,’ she told the BBC.

The nurse said she was told it would take 10 days for the vaccine to offer some protection and reduce the risk of transmission, but three weeks later she began to feel unwell.

She had ‘quite severe symptoms’ of a bad cough, high temperature and breathlessness and was ‘shocked’ when she tested positive.

Deputy Chief Executive of Hywel Dda health board, Dr Philip Kloer, said that while a Covid vaccine ‘reduces your chance of suffering’ from the virus, no vaccine is ever 100% effective

He added that some people may contract Covid-19 immediately before having the vaccine without knowing it, or in the week or two following vaccination as your body builds up protection.

People who have had Covid vaccines are being warned to still take care. It comes amid concern about new guidance to delay second doses in order to prioritise giving as many people as possible the first dose.

The original advice was that people would need the second dose of the Pfizer vaccine three weeks after the first injection.

But that changed last month to 12 weeks between doses. The UK’s chief medical officers defended the move, saying the Pfizer jab gives ‘considerable protection’ after the first dose.