Infectious disease specialist Professor Salim Abdool Karim, who chairs the government's advisory committee on Covid-19, has warned South Africans to not "underestimate the enemy", pointing out that conditions in the country are favourable for the spread of the disease.Speaking at the Data@Breakfast seminar on Friday, Karim said there is no way to get around Covid-19.He said while some thought the virus could be tackled head-on, eliminated through herd immunity (by allowing natural infection) or fought with partial protection measures just for the elderly, these approaches have not been effective."Those who have taken this condition seriously, understand that it's reproductive rate of between two and three [people] gives it an edge over anything we could do.Sitting duck "In a population that has absolutely no protection, zero antibodies that are effective against this virus, everyone is a sitting duck, everyone is at risk. So, you have to treat it like that… you need to put in place measures that deal with that kind of approach," Karim said.The reality was that no one was ready for Covid-19, not even South Africa, Karim said."Nobody ever thought that we would need to deal with something like this. We all thought we were going to deal with something like flu.READ | Covid-19 in SA: Life is not going to be what it once was, says Prof Karim"In the US, which has among the best pandemic preparedness, you just need to look at their epidemic to know how badly that's going," he added. The nation needs to take this threat seriously, Karim said, adding that the government's response to the pandemic was impressive. "I'm impressed that the powers that be took it so seriously. They didn't need to be convinced, they didn't waffle around, they didn't procrastinate. They were decisive, they made decisions, they took the consequences of those decisions..."However, he warned that "we have not escaped this bullet", we have only postponed its impact.No protection"We have a nation that has all the conditions for the spread of this virus, we have no protection in a form of a vaccine or natural antibodies. "We are going to have to find a way to push it as far back as possible because we are going to need time to prepare because we were never prepared for this and in fact no country was," Karim said.He added that South Africa took a different approach to the pandemic and has been proactive and have studied the movement of the virus carefully.These studies, however, are being conducted in a "data-free zone" - not backed by evidence because there simply is not enough."Whether we're right or wrong, time will tell. History will judge us. I don't claim that we are not making mistakes. If you don't make mistakes in tackling a disease of this nature that means you're not being sufficiently proactive.""When you're trying to get ahead of this epidemic, you're doing this in a data-free zone, you actually don't know what the net effect will be," Karim said.