Bill Gates, who last week said he’s stepping down from the board of Microsoft to devote more time to philanthropy, told Reddit users on Wednesday that the coronavirus shutdown could last as long as 10 weeks -- if things go well.

“If a country does a good job with testing and ‘shut down’ then within 6-10 weeks they should see very few cases and be able to open back up,” he said.

Gates, whose foundation has committed up to $100 million to help with the global COVID-19 response, used the Ask Me Anything event to give his thoughts on issues including social distancing, vaccines and the economic fallout.

On what worries him the most:

• “I worry about all the economic damage but even worse will be how this will affect the developing countries who cannot do the social distancing the same way as rich countries and whose hospital capacity is much lower.”

On what people can do to help:

• “A big thing is to go along with the ‘shut down’ approach in your community so that the infection rate drops dramatically to let us go back to normal as soon as possible...We do need to stay calm even though this is an unprecedented situation.”

On the potential use of chloroquine:

• “There are a lot of therapeutic drugs being examined. This is one of many but it is not proven. If it works we will need to make sure the finite supplies are held for the patients who need it most.”

On when we may see a vaccine:

• “The first vaccines we get will go to health care workers and critical workers. This could happen before 18 months if everything goes well but we and [coronavirus task force member Anthony] Fauci and others are being careful not to promise this when we are not sure. The work is going at full speed.”

On when the economy will recover:

• “The economic impact of the ‘shut down’ will be large but if it is done well (including the testing piece which I keep mentioning) eventually we can open back up.”