Christine Loscher, professor of immunology at DCU, joins us on this week's episode to examine the need for booster shots. How much does the efficacy of initial jabs wane, how much does the booster top them up, and what type of lasting immunity could we have against Covid as a result? Also, will they turn the tide of the recent rise in case numbers?The Explainer is brought to you by The Journal. Providing open access to valuable journalism in Ireland has been the aim of The Journal for a decade. You can contribute to ensure we can keep questioning, investigating, debunking, explaining and informing at www.thejournal.ie/contribute/