of 150 health care workers of the shiba medical center to receive the fourth dose of the vaccine. it's not the much publicized rollout of the fourth shot campaign, but it could be a step in that direction. that, at least, is what prime minister seems to want. last week, he welcomed the decision by a panel of experts to recommend the additional booster for over 60s, health workers and people with suppressed immune systems, but the health ministry's director general has yet to sign it off. some health experts remain unconvinced. >> i didn't think that it's right, right now, at this moment. it may change in a week, you know, it depends on what we see is happening in england, what's happening right now here. if we see that there's more severe disease, maybe it will be correct. i think that's why it's so important to start research as soon as possible. >> reporter: initial results from the study are expected by the end of the week, by which time, israel's rising covid case