Mr Buffett’s company had stakes valued at more than $1.8bn each in AbbVie, Bristol-Myers Squibb and Merck at the end of the quarter, and about $136m in Pfizer. Berkshire omitted some confidential information with its routine regulatory filing.

The 90-year-old has been cautious during the pandemic, saying in May that his then-record cash pile was not that big when considering the worst-case possibilities.

Mr Buffett has since deployed cash in Japan and into natural gas assets, and bought back Berkshire shares.

His friend Bill Gates, a former Berkshire board member, has been donating through his foundation to help fund vaccine efforts.

The Berkshire boss dumped airline stocks and sold financials earlier in the crisis. His company continued to pare bank holdings in the third quarter, trimming its Wells Fargo stake and slashing its JPMorgan investment by 96pc.

Berkshire has been chipping away at its Wells Fargo stake in recent months after more than three decades holding onto that bet. It owned about 127m shares at the end of September – a marked shift for an investment that once ranked as Berkshire’s biggest.

Berkshire also took a $276m stake in T-Mobile US during the third quarter.